Replace SVGs of LaTeX to just LaTeX

[utensil]

This should supersede #415

[utensil]

For light mode:

For dark mode:

[utensil]

The issue is that this doesn't work for the Sphinx doc yet:

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.77%. Comparing base (08cf8ca) to head (9c8facc).

❗ Current head 9c8facc differs from pull request most recent head ddf95fb. Consider uploading reports for the commit ddf95fb to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #503   +/-   ##
=======================================
  Coverage   77.77%   77.77%           
=======================================
  Files          17       17           
  Lines        4193     4193           
=======================================
  Hits         3261     3261           
  Misses        932      932           

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[utensil]

Now we have a very interesting problem that Github doesn't accpet ^ in \texttt but mdinclude will display \^{} as is.

[utensil]

One improvement of using sphinx_mdinclude is the TOC

v.s.