Adds the debugger info

Author: orta

README.md

@@ -10,7 +10,7 @@ If you are completely new to the TypeScript codebase, this YouTube video covers
 
 <a href='https://www.youtube.com/watch?v=X8k_4tZ16qU&list=PLYUbsZda9oHu-EiIdekbAzNO0-pUM5Iqj&index=4'><img src="https://user-images.githubusercontent.com/49038/140491214-720ce354-e526-4599-94ec-72cdbecc2b01.png" /></a>
 
-From there, you can start in the [First Steps to Contributing to the TypeScript Repo](./first_steps.md) consult the [Glossary](./GLOSSARY.md) or dive directly into the [`./codebase/`](./codebase) or [`./systems/`](./systems) folders.
+From there, you can start in the [First Steps to Contributing to the TypeScript Repo](https://github.com/microsoft/TypeScript-Compiler-Notes/tree/main/intro#the-typescript-compiler) consult the [Glossary](./GLOSSARY.md) or dive directly into the [`./codebase/`](./codebase) or [`./systems/`](./systems) folders.
 
 ## Asking Questions
 

first_steps.md

@@ -214,10 +214,14 @@ the codebase for the key in that file. E.g:
 
 ### Embrace the debugger
 
+You'll probably spend a good amount of time in the debugger, if this is completely new to you. [Here is a video from](https://www.youtube.com/watch?v=ChQ_sYjU8tU)
+[@alloy](https://github.com/alloy) covering the usage of the debugger inside VS Code, what the buttons do and how it all works.
+
 To test it out the debugger, open up `src/compiler/checker.ts` find
 `function checkSourceFileWorker(node: SourceFile) {` and add a `debugger` statement on the first line in the
 function.
 
+
 ```diff
 function checkSourceFileWorker(node: SourceFile) {
 +   debugger