Add @jupyter/eslint-plugin

[Darshan808]

Description

This PR integrates @jupyter/eslint-plugin into the Jupyter Notebook codebase.

The plugin is being actively developed to catch common issues and enforce best practices across Jupyter frontend projects, including JupyterLab, Notebook, and extensions. An early version is now available on npm, and this PR enables us to start validating the Notebook codebase against these rules.

Code changes

• Updated eslint.config.mjs to include the @jupyter/eslint-plugin.
• Enabled the following rules:

'jupyter/command-described-by': 'warn',
'jupyter/plugin-activation-args': 'error',
'jupyter/plugin-description': 'warn',

These settings follow the recommended configuration for Jupyter extensions.
We may consider making command-described-by and plugin-description stricter (error) if we decide to enforce them strictly across the codebase.

User-facing changes

None

Backwards-incompatible changes

None

[github-actions]

👈 Launch a Binder on branch Darshan808/notebook/include-jupyter-eslint-plugin