docs: switch to myst-parser

[Borda]

Before submitting

• Was this discussed/approved via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

What does this PR do?

Converting to MyST-Parser
see more info - readthedocs/recommonmark#221

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in Github issues there's a high chance it will not be merged.

Did you have fun?

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[codecov]

Codecov Report

Merging #177 (e1be5da) into master (77c789f) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #177   +/-   ##
=======================================
  Coverage   79.75%   79.75%           
=======================================
  Files          90       90           
  Lines        2865     2865           
=======================================
  Hits         2285     2285           
  Misses        580      580           

Flag	Coverage Δ
Linux	79.75% <ø> (ø)
Windows	79.75% <ø> (ø)
cpu	79.75% <ø> (ø)
macOS	79.75% <ø> (ø)
pytest	79.75% <ø> (ø)

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