Fix broken links in the website (https://documentdb.io) for the quick start links that link to .md files

[abinav2307]

Reference links to .md files within other .md files need to be fixed for the purpose of the website.

There is a need for a temporary fix to remove the .md reference links within the .md files to be direct links to pages in the website (https://documentdb.io). This temporary fix will immediately address broken links in the website.

A longer-term design needs to be implemented to correctly handle references to other .md files in the website when dynamically generating content on the browser from the docs repo.

[guanzhousongmicrosoft]

The immediate ask here is done as of #65: there are now zero relative .md links anywhere in the repository.

$ grep -rn '](\.\{1,2\}/[^)]*\.md)' --include="*.md" . | wc -l
0

#57 fixed 19 of these and settled the convention — absolute https://documentdb.io/docs/reference/.../%24bucket/ URLs. #65 cleaned up 17 more that had been introduced since, across the recent aggregation pages, where the relative form resolved against the page's own directory and 404'd.

Leaving this open for the second half of the ask: the longer-term design so that a plain [text](other-page.md) reference works when the site generates pages from this repo. Until that exists, the absolute form is the convention, and new relative .md links will keep silently 404ing — a lint check in CI would catch them at review time rather than in production.