Apply suggestions from code review

Co-authored-by: Frédéric Collonval <[email protected]>

Author: jtpio

.github/workflows/main.yml

@@ -272,7 +272,7 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-pip-
       - name: Install the Python dependencies
-        run: python -m pip install --pre jupyterlab
+        run: python -m pip install jupyterlab
       - name: Bootstrap the jlpm deps
         run: jlpm
       - name: Build all the extensions

basics/hello-world/README.md

@@ -91,7 +91,7 @@ called `@jupyterlab/application`. The dependency of your extension on this
 package is declared in the file `package.json`:
 
 ```json5
-// package.json#L44-L46
+// package.json#L46-L48
 
   "watch:src": "tsc -w"
 },