docs: fix null type descriptions in Introspection docs

We're currently specifying descriptions in the `StarWarsSchema` using comments, which is causing them to resolve as `null` when we run introspection queries, like in the [last example on the Introspection docs page](https://graphql.org/learn/introspection/).

The [newer versions of the spec](https://spec.graphql.org/October2021/#sec-Descriptions) outline that descriptions should use a `BlockString`, so this change updates all the descriptions to use `BlockString` instead of comments.

Looks like, alternatively, we could have specified `commentDescriptions` in our invocation of `makeExecutableSchema`, but we might as well make our schema consistent with the current way of specifying descriptions in the spec.

Fixes graphql#1496

src/components/Marked/swapiSchema.tsx

@@ -27,7 +27,9 @@ const typeDefs = /* GraphQL */ `
     mutation: Mutation
   }
 
-  # The query type, represents all of the entry points into our object graph
+  """
+  The query type, represents all of the entry points into our object graph
+  """
   type Query {
     hero(episode: Episode): Character
     reviews(episode: Episode!): [Review]
@@ -38,155 +40,251 @@ const typeDefs = /* GraphQL */ `
     starship(id: ID!): Starship
   }
 
-  # The mutation type, represents all updates we can make to our data
+  """
+  The mutation type, represents all updates we can make to our data
+  """
   type Mutation {
     createReview(episode: Episode, review: ReviewInput!): Review
   }
 
-  # The episodes in the Star Wars trilogy
+  """
+  The episodes in the Star Wars trilogy
+  """
   enum Episode {
-    # Star Wars Episode IV: A New Hope, released in 1977.
+    """
+    Star Wars Episode IV: A New Hope, released in 1977.
+    """
     NEWHOPE
 
-    # Star Wars Episode V: The Empire Strikes Back, released in 1980.
+    """
+    Star Wars Episode V: The Empire Strikes Back, released in 1980.
+    """
     EMPIRE
 
-    # Star Wars Episode VI: Return of the Jedi, released in 1983.
+    """
+    Star Wars Episode VI: Return of the Jedi, released in 1983.
+    """
     JEDI
   }
 
-  # A character from the Star Wars universe
+  """
+  A character from the Star Wars universe
+  """
   interface Character {
-    # The ID of the character
+    """
+    The ID of the character
+    """
     id: ID!
 
-    # The name of the character
+    """
+    The name of the character
+    """
     name: String!
 
-    # The friends of the character, or an empty list if they have none
+    """
+    The friends of the character, or an empty list if they have none
+    """
     friends: [Character]
 
-    # The friends of the character exposed as a connection with edges
+    """
+    The friends of the character exposed as a connection with edges
+    """
     friendsConnection(first: Int, after: ID): FriendsConnection!
 
-    # The movies this character appears in
+    """
+    The movies this character appears in
+    """
     appearsIn: [Episode]!
   }
 
-  # Units of height
+  """
+  Units of height
+  """
   enum LengthUnit {
-    # The standard unit around the world
+    """
+    The standard unit around the world
+    """
     METER
 
-    # Primarily used in the United States
+    """
+    Primarily used in the United States
+    """
     FOOT
   }
 
-  # A humanoid creature from the Star Wars universe
+  """
+  A humanoid creature from the Star Wars universe
+  """
   type Human implements Character {
-    # The ID of the human
+    """
+    The ID of the human
+    """
     id: ID!
 
-    # What this human calls themselves
+    """
+    What this human calls themselves
+    """
     name: String!
 
-    # Height in the preferred unit, default is meters
+    """
+    Height in the preferred unit, default is meters
+    """
     height(unit: LengthUnit = METER): Float
 
-    # Mass in kilograms, or null if unknown
+    """
+    Mass in kilograms, or null if unknown
+    """
     mass: Float
 
-    # This human's friends, or an empty list if they have none
+    """
+    This human's friends, or an empty list if they have none
+    """
     friends: [Character]
 
-    # The friends of the human exposed as a connection with edges
+    """
+    The friends of the human exposed as a connection with edges
+    """
     friendsConnection(first: Int, after: ID): FriendsConnection!
 
-    # The movies this human appears in
+    """
+    The movies this human appears in
+    """
     appearsIn: [Episode]!
 
-    # A list of starships this person has piloted, or an empty list if none
+    """
+    A list of starships this person has piloted, or an empty list if none
+    """
     starships: [Starship]
   }
 
-  # An autonomous mechanical character in the Star Wars universe
+  """
+  An autonomous mechanical character in the Star Wars universe
+  """
   type Droid implements Character {
-    # The ID of the droid
+    """
+    The ID of the droid
+    """
     id: ID!
 
-    # What others call this droid
+    """
+    What others call this droid
+    """
     name: String!
 
-    # This droid's friends, or an empty list if they have none
+    """
+    This droid's friends, or an empty list if they have none
+    """
     friends: [Character]
 
-    # The friends of the droid exposed as a connection with edges
+    """
+    The friends of the droid exposed as a connection with edges
+    """
     friendsConnection(first: Int, after: ID): FriendsConnection!
 
-    # The movies this droid appears in
+    """
+    The movies this droid appears in
+    """
     appearsIn: [Episode]!
 
-    # This droid's primary function
+    """
+    This droid's primary function
+    """
     primaryFunction: String
   }
 
-  # A connection object for a character's friends
+  """
+  A connection object for a character's friends
+  """
   type FriendsConnection {
-    # The total number of friends
+    """
+    The total number of friends
+    """
     totalCount: Int
 
-    # The edges for each of the character's friends.
+    """
+    The edges for each of the character's friends.
+    """
     edges: [FriendsEdge]
 
-    # A list of the friends, as a convenience when edges are not needed.
+    """
+    A list of the friends, as a convenience when edges are not needed.
+    """
     friends: [Character]
 
-    # Information for paginating this connection
+    """
+    Information for paginating this connection
+    """
     pageInfo: PageInfo!
   }
 
-  # An edge object for a character's friends
+  """
+  An edge object for a character's friends
+  """
   type FriendsEdge {
-    # A cursor used for pagination
+    """
+    A cursor used for pagination
+    """
     cursor: ID!
 
-    # The character represented by this friendship edge
+    """
+    The character represented by this friendship edge
+    """
     node: Character
   }
 
-  # Information for paginating this connection
+  """
+  Information for paginating this connection
+  """
   type PageInfo {
     startCursor: ID
     endCursor: ID
     hasNextPage: Boolean!
   }
 
-  # Represents a review for a movie
+  """
+  Represents a review for a movie
+  """
   type Review {
-    # The number of stars this review gave, 1-5
+    """
+    The number of stars this review gave, 1-5
+    """
     stars: Int!
 
-    # Comment about the movie
+    """
+    Comment about the movie
+    """
     commentary: String
   }
 
-  # The input object sent when someone is creating a new review
+  """
+  The input object sent when someone is creating a new review
+  """
   input ReviewInput {
-    # 0-5 stars
+    """
+    0-5 stars
+    """
     stars: Int!
 
-    # Comment about the movie, optional
+    """
+    Comment about the movie, optional
+    """
     commentary: String
   }
 
   type Starship {
-    # The ID of the starship
+    """
+    The ID of the starship
+    """
     id: ID!
 
-    # The name of the starship
+    """
+    The name of the starship
+    """
     name: String!
 
-    # Length of the starship, along the longest axis
+    """
+    Length of the starship, along the longest axis
+    """
     length(unit: LengthUnit = METER): Float
   }