docs: mild adjustments to tutorial 8

docs/TUTORIAL_08.md

@@ -14,7 +14,7 @@ Command Centres can be upgraded into Orbital Commands after the tech requirement
   over-saturates patches for an additional ±220 minerals per minute.
 - It also enables a **Scanner Sweep** which grants vision for a few seconds and reveals cloaked units.
 
-Let's do so and see how to perform these abilities.
+Let's upgrade and see how to perform these abilities.
 
 #### Transform
 
@@ -41,7 +41,7 @@ def on_step
 end
 ```
 
-We start by checking that we have at least one completed barrack, since this is a tech requirement for Orbital Commands.
+We start by checking that we have at least one completed Barrack, since this is a tech requirement for Orbital Commands.
 
 While we only have one base right now (`main_base`), the above code generically loops over every structure of type
 Command Centre.  
@@ -65,7 +65,6 @@ You can smooth this build out more by adjusting the SCV building logic to not qu
 #### Casting and Energy
 
 With the Command Centre upgraded to an Orbital Command, let's call down a MULE.  
-This unit allows over-saturation of a mineral patch and brings us an additional ±220 minerals per minute.
 
 ```ruby
 
@@ -112,7 +111,9 @@ if main_base.unit_type == Api::UnitTypeId::ORBITALCOMMAND
 end
 ```
 
-So far, so good!
+![mule](images/08_terran_upgades_mule.jpg)
+
+So far, so good! We are getting extra income and putting it to use. 
 
 ### Tech Lab Upgrades
 
@@ -129,7 +130,7 @@ Below we keep a simple array of the items we desire and queue them with a series
 As seen above, the names of Id's might be different than what you know them by. We use the names the client gives us.  
 To find the name you are looking for, you can either ask in the Discord or dig for yourself...
 
-The {Sc2::Data} shows **all available id's** in the game. At runtime you can inspect the Id's of the following:  
+The {Sc2::Data} object gives us **all available id's** in the game. At runtime you can inspect the Id's of the following:  
 `data.abilities`, `data.units`, `data.upgrades`, `data.buffs` and `data.effects`.
 
 {Api::TechTree} has statically generated tech tree information.  
@@ -152,7 +153,7 @@ some_structure.research(upgrade_id:, queue_command: false) # Tells specific Unit
 structures.research(upgrade_id:, queue_command: false) # Tells Unit Group to research upgrade
 ```
 
-#### Do your own research
+#### For science!
 
 Let's see how we can put some of these to use, given we have an array of desired upgrade ids:
 
@@ -193,11 +194,12 @@ After all those checks we can simply hand over the research command to all tech
 `structures.select_type(Api::UnitTypeId::BARRACKSTECHLAB).research(...)`,  
 but let's use the {Api::TechTree} class to tell us which structures we need to select.
 
-This way, if we had Factory or Starport upgrades, our bot can dynamically select the correct building, instead of hard-coded to Barracks' Tech Labs.  
+This way, if we had Factory or Starport upgrades, our bot can dynamically select the correct building, instead of hard-coded to Barracks' Tech Labs.
+
 As mentioned before `Api::TechTree` hold information about the technology tree. It's useful for finding
 what-creates-what and how.  
 Here, with `upgrade_researched_from`, we can find out which research structure is responsible for doing a specific
-upgrade.
+upgrade:
 
 ```ruby
 research_structure_type = Api::TechTree.upgrade_researched_from(upgrade_id: upgrade_id)
@@ -251,7 +253,7 @@ Run it a few times and watch! We beat Medium frequently and even sometimes setti
 
 ---
 
-### Terran Conclusion
+## Conclusion
 
 There are a ton of things we can still do with this build. The unnecessary or unused gas comes to mind first. Adding Factory/Starport units, even or taking another base.