Set unicode supporting fonts in tex template

[jvntf]

Adds support for unicode characters inside and outside of LaTeX math mode by setting main font and math font to one that includes a large unicode alphabet. Emojis are not supported, but we can support them with something like this.
Perhaps this solution is crude?

Re @guidorice comment, this will work w/r/t to PDF output even though KaTeX shows a client side error (probably catchable).

[danielfdsilva]

I don't think we need to support emojies. It seems unlikely that an ATBD will use them. We're probably better off stripping them out.

Not sure how to test this. Can you provide some steps?

[jvntf]

@danielfdsilva I have tested as suggested here

In a text section add unicode symbols such as 𝛾Γ
Add a latex section with \gamma \Gamma and they should both render the same content.

Based on what I've read, there is no catchall for this. i.e. our support for unicode symbols is limited by the font chosen. Perhaps we can choose fonts based on what unicode symbols are input? I can look into this, but it is certainly more complicated than choosing a font with pretty good coverage.

[danielfdsilva]

This is working as expected.
I'd say we choose a font that has a sufficient unicode support and document that:

• The font that was chosen, listing (or maybe linking to) the supported unicode characters.
• What happens when a missing character is used

@jvntf Do you agree? Can you add this so this is complete?

[jvntf]

I agree, but first want to clarify intended behavior. Are we supporting unicode in text mode, math mode, or both? I suggest to only support unicode in text mode and let LaTeX handle rendering math symbols in math mode (default functionality, LaTeX macros are a safer bet in math mode).

best list i've seen of unicode math symbols supported by Latin Modern Math

[danielfdsilva]

@jvntf your suggestion sounds good. Go ahead.
If users have a different need, we'll adapt in the future

[danielfdsilva]

@jvntf This looks good, but can we have the documentation in the README is a user facing format.
It would be good to be explicit about what is supported and what happens in case an invalid character is used.