Support GitLab's math blocks

[martinzuern]

It would be great to have an option that Typora's markdown complies with GitLab flavored markdown, as defined here: https://docs.gitlab.com/ee/user/markdown.html#math

Biggest difference is that math blocks are defined like this:

This math is inline $`a^2+b^2=c^2`$.

This is on a separate line (backslash only for escaping here)
\```math
a^2+b^2=c^2
\```

Also, GitLab is using KaTeX

[abnerlee]

It's a very uncommon markdown syntax. We won't support it naively. Maybe make it possible through #162 would be better

[analog-cbarber]

It is uncommon except that anyone using math expressions with gitlab will be using this syntax, so you cannot simply write this off as crazy. I would love to use your editor, but for me, this is an absolute requirement.

It is not at all clear that you have any intention of actually implementing a plugin API or have any idea what form they would take.

[lgrcia]

I would also love to have this feature. If syntax variations are common having custom syntax config files (as with themes) would be handy.

[analog-cbarber]

I have discovered that Visual Studio Code, which is free, has a 'Markdown Prefix Enhanced' extension that supports GitLab math markup, so that is what I am now using.

[bingyupiaoyao]

I would also love to have this feature, it is very important~

[abnerlee]

will put into #2448

[abnerlee]

can be covered in #63

[bmalbusca]

+1 upvote on this!