docs: add terraform-docs

[nitrocode]

what

• docs: add terraform-docs (preview of docs)

why

• Document all input variables include var.runtime
• Adding a comment in .python-version causes github action to fail since the actions do not support comments

references

• Closes Use terraform-docs to document inputs/outputs #73
• terraform-docs
  • https://github.com/antonbabenko/pre-commit-terraform?tab=readme-ov-file#terraform_docs
  • https://terraform-docs.io/user-guide/configuration/
  • https://github.com/terraform-docs/terraform-docs
  • https://github.com/terraform-docs/terraform-docs/releases/tag/v0.19.0
• install-gh-release action
  • https://github.com/jaxxstorm/action-install-gh-release
  • https://github.com/marketplace/actions/install-a-binary-from-github-releases
• limitation with actions/setup-python The action fails if the .python-version (passed into python-version-file input) contains a comment actions/setup-python#949

[github-actions]

Integration Test Results

20 tests  ±0   20 ✅ ±0   6s ⏱️ ±0s
 1 suites ±0    0 💤 ±0 
 1 files   ±0    0 ❌ ±0 

Results for commit 23b5fc0. ± Comparison against base commit e168234.

♻️ This comment has been updated with latest results.

[github-actions]

Test Results

79 tests  ±0   79 ✅ ±0   0s ⏱️ ±0s
 1 suites ±0    0 💤 ±0 
 1 files   ±0    0 ❌ ±0 

Results for commit 23b5fc0. ± Comparison against base commit e168234.

♻️ This comment has been updated with latest results.

[paulschwarzenberger]

In my other open-source project, I implemented a Terraform docs GitHub Action which automatically updates every time a PR is submitted, and writes to a separate file, rather than the top-level README, so as to stop the README becoming overly long.
I quite like this approach as it avoids separate PRs for Terraform Docs - what do you think?
See example workflow

[paulschwarzenberger]

LGTM