Use Hack as monospace font with good unicode coverage

[jedbrown]

This allows unicode in code blocks, as is especially popular in Julia submissions (https://github.com/openjournals/joss/issues/963).

https://sourcefoundry.org/hack/

[arfon]

Thanks for opening this PR @jedbrown, and apologies it has taken me so long to get to this.

Unfortunately this PR is currently blocked by the fact that we don't actually use the Dockerfile for compiling the actual JOSS papers. The LaTeX/Pandoc environment for the real papers is built using these Heroku buildpacks.

We could try and modify these buildpacks to build the font from source (i.e., follow this guide https://github.com/source-foundry/Hack#linux) but I'd rather invest energy into migrating Whedon to use the Dockerfile directly (which is work that @xuanxu is actively doing right now).

So :+1: to this change, just not quite yet.

[jedbrown]

Thanks. Is there an issue or PR to watch, such that this can move forward once it's complete? I don't see one in this repo and don't want this to get lost.

[arfon]

Yeah, this is the right issue to watch: https://github.com/openjournals/buffy/issues/46