ci: Add markdownlint, test_converting_readme, and build_docs workflows

[spetrosi]

• markdownlint runs against README.md to avoid any issues with converting it to HTML
• test_converting_readme converts README.md > HTML and uploads this test artifact to ensure that conversion works fine
• build_docs converts README.md > HTML and pushes the result to the docs branch to publish dosc to GitHub pages site.
• Fix markdown issues in README.md

Signed-off-by: Sergei Petrosian spetrosi@redhat.com

[codecov[bot]]

Codecov Report

Patch and project coverage have no change.

Comparison is base (e4ba6e0) 61.05% compared to head (7efe527) 61.05%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #173 +/- ## ======================================= Coverage 61.05% 61.05% ======================================= Files 2 2 Lines 909 909 ======================================= Hits 555 555 Misses 354 354 ``` | Flag | Coverage Δ | | |---|---|---| | sanity | `∅ <ø> (?)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=linux-system-roles#carryforward-flags-in-the-pull-request-comment) to find out more.

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