Fix some markdown oddities (#203)

doc/DRAFT_Intro_Docs.md

@@ -84,7 +84,7 @@ If you want to change the shifted character on a key, the change will need to be
 
 Another thing to be aware of is the prog key. It sends a special signal to the keyboardio when you hold it down that allows the firmware to be over-written. 
 
-[comment]:<> (@jesse @algernon are there more limitations that should be documented?)
+<!-- (@jesse @algernon are there more limitations that should be documented?) -->
 
 <h2>Install Arduino support</h2>
 
@@ -108,7 +108,7 @@ The Arduino system has been designed to be accessible to people at all skill lev
 
  2. Open the “Arduino” menu and click on “Preferences”
 
- 3. At the bottom of the "Settings" tab is the 'Additional Board Manager URLs` box. Paste this into it:  https://raw.githubusercontent.com/keyboardio/boardsmanager/master/package\_keyboardio\_index.json then click ‘OK’ to close the dialog
+ 3. At the bottom of the "Settings" tab is the 'Additional Board Manager URLs' box. Paste this into it:  https://raw.githubusercontent.com/keyboardio/boardsmanager/master/package_keyboardio_index.json then click ‘OK’ to close the dialog
 
  4. the ‘Tools’ menu, click on ‘Board’ and then click on ‘Boards Manager’