Implement linksmith inventory and linksmith output-formats

[amotl]

About

From the Linksmith RFC,
a little bit of both.

• People are asking for Markdown Output, but sphobjinv will unlikely implement it.
• People are asking for Multi-Project Support, but sphobjinv doesn’t have it.

To be continued.

Details

Under the hood, many output formats are heavily based on what sphobjinv provides. Thanks a stack, @bskinn!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (b09120a) to head (d77b191).

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Additional details and impacted files

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  Files            1         8     +7     
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+ Hits             2       248   +246     

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unittests	100.00% <100.00%> (ø)

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[bskinn]

Check out bskinn/sphobjinv#283 -- @machow proposed a better JSON output format that might(?) make for more attractive YAML.

I need to actually implement that...

[amotl]

Thank you very much. I knew you would have excellent suggestions about it. 💯

I merged this PR early, to get something working into main before going afk, but that does not mean I will not consider any other suggestions here, also in retrospective. Thanks!

[amotl]

Coming from our needs at CrateDB, for multi-project use, this incantation implements the best of DWIM we can have for now. Others may find this viable as well.

linksmith inventory \
  https://github.com/crate/crate-docs/raw/main/registry/sphinx-inventories.txt \
  --format=html+table > crate-sphinx-overview.html

open crate-sphinx-overview.html