Links in updated markdown open in a new tab

[gante]

Description

Links in updated markdown open in a new tab :D See the original issue for more info

Closes: #3234

NOTES/QUESTIONS:

1. Regarding testing, the instructions in CONTRIBUTING.md seem to be updated (e.g. there is no .circleci folder, so bash scripts/run_circleci.sh can't run). I was unable to run the test suite locally but can confirm that the problems were fixed locally.
2. IDK how to test this, suggestions are appreciated :)

P.S.: TIL about the ability to run gradio app.py. OMG, what a superpower, kudos to whoever had the idea <3

Checklist:

• [x] I have performed a self-review of my own code
• [x] I have added a short summary of my change to the CHANGELOG.md
• [x] My code follows the style guidelines of this project
• [x] I have commented my code in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes

[gradio-pr-bot]

All the demos for this PR have been deployed at https://huggingface.co/spaces/gradio-pr-deploys/pr-3236-all-demos

[abidlabs]

Thanks for the fix @gante! We'll take a look at this PR soon.

Btw how'd you learn about gradio app.py? Perhaps we should feature it more prominently in the docs

[gante]

@abidlabs markdown-related tests are failing, I'm going to have a look and attempt to fix them.

Re gradio app.py, found it in the CONTRIBUTING.md page :)

[gante]

@abidlabs test fixed -- and the fixed test now tests that the feature is working as intended

[abidlabs]

Great, thanks for the PR @gante! Let me take a look at it and we can merge it in soon

[abidlabs]

I consolidated some of the markdown code that we had across different files, and tested. LGTM. Will merge after the CIs pass.

[abidlabs]

Tests passing, thanks again for the PR @gante!