Remove dockerfile from documentation (#4046)

* Remove Dockerfile from CONTRIBUTING.md

Remove two lines referencing an absent Dockerfile.

* Remove Dockerfile from debugging.md

Remove one phrase referencing an absent Dockerfile

CONTRIBUTING.md

@@ -62,9 +62,6 @@ There are some pre-defined tasks in [tasks.json](.vscode/tasks.json)
 - Test - (there is no shortcut, you'll need to make one) - Runs `Cargo Test`.
   I personally set a shortcut of shift+cmd+option+T (or shift+ctrl+alt+T)
 
-If you don't want to install everything on your machine, you can use the Dockerfile.
-Start VSCode in container mode (you may need the docker container plugin) and use the Dockerfile.
-
 ## Testing
 
 Boa provides its own test suite, and can also run the official ECMAScript test suite. To run the Boa test

docs/debugging.md

@@ -110,8 +110,7 @@ more information [here][blog_debugging].
 
 ### LLDB Manual debugging
 
-You can also use rust-lldb. The `Dockerfile` already has this enabled, you
-should be able to use that environment to run your code.
+You can also use rust-lldb. You should be able to use that environment to run your code.
 
 ```
 rust-lldb ./target/debug/boa [arguments]