Add links to issues in new contributors documentation.

[alex-rand]

This fixes issue #6561 in the pymc repo.

Added two links: one for issues with the beginner friendly tag, and another for all issues.

@jessegrabowski this seemed like a good first issue, per your suggestion.

📚 Documentation preview en 📚: https://pymc-data-umbrella--228.org.readthedocs.build/en/228/

📚 Documentation preview es 📚: https://pymc-data-umbrella-es--228.org.readthedocs.build/es/228/

📚 Documentation preview pt 📚: https://pymc-data-umbrella-pt--228.org.readthedocs.build/pt/228/

[welcome]

💖 Thanks for opening this pull request! 💖 The Data Umbrella community really appreciates your time and effort to contribute to the project. Please make sure you have read our Contributing Guidelines and filled in our pull request template to the best of your ability.

[reshamas]

@alex-rand Thank you for taking the time to submit this PR.

We are closing this for a few reasons.

Recommend watching this video on best practices.
(Ex 1: Do not submit a PR with so many files because it is difficult to review: https://youtu.be/dyxS9KKCNzA).

(Ex 2: ask maintainers if they want the whitespace removed first before submitting changes to 100+ files.)

You can submit a pull request with edits to this one file:
contributing/tutorials/environment_setup.md

[alex-rand]

Yikes, thanks for reviewing. Not sure what happened here, I'll try again in a new PR.