Fixes #2369 Update environment setup documentation

[cindyorangis]

Issue This PR Addresses

Closes #2369 Outdated environment setup documentation

Type of Change

• Bugfix: Change which fixes an issue
• New Feature: Change which adds functionality
• Documentation Update: Change which improves documentation
• UI: Change which improves UI

Description

I added a neat table of content at the top of our environment-setup because honestly, it was becoming hard to read and navigate. I also updated the instructions for some of the steps to reflect the new changes that were added so new and returning Telescope developers can get their environment up and running correctly.

Checklist

• Quality: This PR builds and passes our npm test and works locally
• Tests: This PR includes thorough tests or an explanation of why it does not
• Screenshots: This PR includes screenshots or GIFs of the changes made or an explanation of why it does not (if applicable)
• Documentation: This PR includes updated/added documentation to user exposed functionality or configuration variables are added/changed or an explanation of why it does not(if applicable)

[humphd]

Really good, just one thing I think we should add.

[humphd]

@cindyledev rebase, squash, and merge when ready! Thanks for doing this, it's awesome.

[cindyorangis]

Thanks for the reviews! I will merge after the checks have passed