Add new "Explore Codebase" page for DG

[yyccbb]

What is the purpose of this pull request?

• [x] Documentation update

#2605 #2066 #1346

Overview of changes:

• New "Exploring Codebase" page added, containing instructions for new developers to explore the codebase.
• Instructions on setting up debugging configurations for Jetbrains IDEs added.
• Instructions on setting up debugging configurations for VSCode to be done by @gerteck
• Instructions on ingesting the codebase with LLMs to be done by @yyccbb
• Some updates to the original "Workflow" page to be done by @yyccbb

Anything you'd like to highlight/discuss: NA

Testing instructions: NA

Proposed commit message: (wrap lines at 72 characters) Add new "Explore Codebase" page for DG

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Checklist: :ballot_box_with_check:

• [x] Updated the documentation for feature additions and enhancements
• [x] Added tests for bug fixes or features
• [x] Linked all related issues
• [x] No unrelated changes

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Reviewer checklist:

Indicate the SEMVER impact of the PR:

• [ ] Major (when you make incompatible API changes)
• [ ] Minor (when you add functionality in a backward compatible manner)
• [ ] Patch (when you make backward compatible bug fixes)

At the end of the review, please label the PR with the appropriate label: r.Major, r.Minor, r.Patch.

Breaking change release note preparation (if applicable):

• To be included in the release note for any feature that is made obsolete/breaking

Give a brief explanation note about:

• what was the old feature that was made obsolete
• any replacement feature (if any), and
• how the author should modify his website to migrate from the old feature to the replacement feature (if possible).

[gerteck]

I've added the relevant documentation for VS Code testing configuration!