Many Markdown preprocessors, such as the one that Jekyll and GitHub Pages use,
have a "smart quotes" feature. This changes ' to ’ which is an issue for
math containing primes, e.g. f'. This can be worked around by defining a
single character macro which changes them back, e.g. {"’", "'"}.
KaTeX follows LaTeX's rendering of aligned and matrix environments unlike
MathJax. When displaying fractions one above another in these vertical
layouts there may not be enough space between rows for people who are used to
MathJax's rendering. The distance between rows can be adjusted by using
\\[0.1em] instead of the standard line separator distance.
KaTeX does not support the align environment because LaTeX doesn't support
align in math mode. The aligned environment offers the same functionality
but in math mode, so use that instead.
MathJax defines \color to be like \textcolor by default; set KaTeX's
colorIsTextColor option to true for this behavior. KaTeX's default
behavior matches MathJax with its color.js extension enabled.
