Setup Scalar for API documentation

[dhruvkb]

Description

This PR sets up Scalar for API documentation. Scalar is a modern on API documentation.

Testing Instructions

0. Check out this PR and bring up the API services.
1. Visit /v1/scalar/ to see the Scalar interface.

Checklist

• My pull request has a descriptive title (not a vague title likeUpdate index.md).
• My pull request targets the default branch of the repository (main) or a parent feature branch.
• My commit messages follow best practices.
• My code follows the established code style of the repository.
• I added or updated tests for the changes I made (if applicable).
• I added or updated documentation (if applicable).
• I tried running the project locally and verified that there are no visible errors.
• I ran the DAG documentation generator (ov just catalog/generate-docs for catalog
  PRs) or the media properties generator (ov just catalog/generate-docs media-props
  for the catalog or ov just api/generate-docs for the API) where applicable.

Developer Certificate of Origin

Developer Certificate of Origin

Developer Certificate of Origin
Version 1.1

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Developer's Certificate of Origin 1.1

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    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
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    by me, under the same open source license (unless I am
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    in the file; or

(c) The contribution was provided directly to me by some other
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