docs: Small updates 🦃

[nitrocode]

what

• Expose all docs in TOC
• Mention the git::ssh syntax when writing git creds for private modules Support git ssh key authentication #176 (comment)
• Ignore tester and linter gh actions if the PR is a draft
• Mention that --gh-allow-mergeable-bypass-apply flag without required checks will throw an error --gh-allow-mergeable-bypass-apply flag will panic if no required checks on GH branch protection settings #2663
• Show environment variable for all flags

Could go in separate PR(s)

• Mention pre_workflow_run can change atlantis.yaml on the fly but cannot change terraform files and ref Run Atlantis plan in directories modified by pre workflow run #2693
• Mention public blog posts Add company Logos and success histories to the Atlantis page #2626
• Create customizing image doc (awscli v2, tflint, terragrunt, cdktf, checkov, etc)
• API docs Document all API endpoints #2640
• Update terraform versions doc Document that custom workflows don't use correct terraform version #639

why

• Expose all docs in TOC to help spread docs and get updates

references

• Added reference in TOC to these docs
  • https://www.runatlantis.io/docs/faq.html
  • https://www.runatlantis.io/docs/stats.html

[jamengual]

should we remove the 'beta' from the policy checks flag?