update error handling for custom flows guide

[alexisintech]

https://clerk.com/docs/pr/1034/custom-flows/error-handling

[github-actions]

Hey, here’s your docs preview: https://clerk.com/docs/pr/1034

[S3Prototype]

I'm not necessarily opposed to this, but it doesn't seem like we put the interface in a codeblock like this for the other type references.

I think it's smart to add this because the meta property is so complex, but I worry we'll forget that reasoning and in the future feel the need to add codeblocks of entire interfaces in other type docs, which is kind of redundant.

What do you think of adding something like this below the property table?

The meta property consists of the following structure:

 meta?: {
   paramName?: string;
   sessionId?: string;
  emailAddresses?: string[];
   identifiers?: string[];
   zxcvbn?: {
     suggestions: {
       code: string;
       message: string;
     }[];
   };
   permissions?: string[];
 };