Improve grammar and consistency in CONTRIBUTING.md

[lejenhan]

This PR improves the CONTRIBUTING.md file to enhance readability by:

• Fixing grammatical issues
• Ensuring consistent capitalization of tool names and code comments
• Improving sentence consistency and clarity

It follows up on the closed PR #7645, addressing similar grammatical issues with additional fixes. Please let me know if any additional changes are needed, thank you!

[github-actions]

👈 Launch a Binder on branch lejenhan/notebook/doc_update

[Muazislam]

@@ -7,18 +7,17 @@ for a friendly and welcoming collaborative environment.

Setting up a development environment

-Note: You will need NodeJS to build the extension package.
-Note: you will need Node.js to build the extension package.
+Note: You will need Node.js to build the extension package.

The jlpm command is JupyterLab's pinned version of yarn that is installed with JupyterLab. You may use
yarn or npm in lieu of jlpm below.

-Note: we recommend using mamba to speed the creating of the environment.
+Note: We recommend using mamba to accelerate the creation of the environment.

-# create a new environment
+# Create a new environment
mamba create -n notebook -c conda-forge python nodejs -y

-# activate the environment
+# Activate the environment
mamba activate notebook

# Install package in development mode
@@ -74,8 +73,8 @@ jupyter notebook

The development installation described above fetches JavaScript dependencies from [npmjs](https://www.npmjs.com/),
according to the versions in the _package.json_ file.
-However, it is sometimes useful to be able to test changes in Notebook, with dependencies (e.g. `@jupyterlab` packages) that have not yet
+However, it is sometimes useful to be able to test changes in Notebook, with dependencies (e.g., `@jupyterlab` packages) that have not yet
been published.

[yalc](https://github.com/wclr/yalc) can help use local JavaScript packages in your build of
@@ -117,16 +116,16 @@ There are also end to end tests to cover higher level user interactions, located

```bash
cd ui-tests
-#install required packages for jlpm
-jlpm
+# Install required packages using jlpm
+jlpm

-#install playwright
-# Install Playwright
+# Install Playwright
jlpm playwright install

-# start a new Jupyter server in a terminal
+# Start a new Jupyter server in a terminal
jlpm start

-# in a new terminal, run the tests
+# In a new terminal, run the tests
jlpm test