Add readthedocs page for mapca

[eurunuela]

Closes #42 .

This PR adds the documentation related to the package.

[codecov-commenter]

Codecov Report

Merging #46 (1e8a8db) into main (0ae41bb) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main      #46   +/-   ##
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  Coverage   90.42%   90.42%           
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  Files           3        3           
  Lines         282      282           
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  Hits          255      255           
  Misses         27       27           

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[handwerkerd]

Great start! My one general comment is that, as a learning tool, it would be nice to have a few more "why" comments instead of the current "what" comments. That is, you include things like "Step 2: Apply kurtosis threshold of Gaussianity to SVD data to get first estimate of subsampling depth" without saying why this step is happening. This doesn't have to be a textbook level of detail, but a sentence or two at the beginning of each code block explain why each step is done would help.