Add Dockerfile for LaTeX build

[inkydragon]

Fix #2073

• Do we want to update the version of Ubuntu? Maybe use ubuntu:latest
• Do we need a tectonic docker image? juliadocs/documenter-tectonic
  And rename texlive-based image to: juliadocs/documenter-texlive
  Estimated size is 100MB~. And current image is 430MB+
• And I'd like to rename the docker usename to juliadocs

todo

• run PDF build for JuliaDocs/Documenter.jl
• run PDF build for JuliaLang/julia
• release docker image, and update DOCKER_IMAGE_TAG in src/latex/LaTeXWriter.jl

Note:

• I choose MIT OR CC0-1.0 for Dockerfile, Because I think it makes it easy for people to copy and paste

[mortenpi]

Don't we need the fonts, like in the old image?

We also had ENV DEBIAN_FRONTEND noninteractive. I am not 100% sure why though. Maybe @fredrikekre remembers?

[mortenpi]

Pure bikeshed, but I think Docker supports heredocs, which should allow us to get rid of the \s?

[mortenpi]

Yeah, let's update this. Could be conservative and use 22.04 though.

[mortenpi]

Do we need a tectonic docker image? juliadocs/documenter-tectonic. And rename texlive-based image to: juliadocs/documenter-texlive. Estimated size is 100MB~. And current image is 430MB+

Tectonic should be used via a JLL I think, so shouldn't be necessary to have an image?

And I'd like to rename the docker usename to juliadocs

Sounds reasonable.

• I choose MIT OR CC0-1.0 for Dockerfile, Because I think it makes it easy for people to copy and paste

Fine by be. I feel that it's not particularly copyrightable anyway, for what it's worth. So CC0 seems suitable.

[mortenpi]

We also need a LABEL for GHCR? https://docs.github.com/en/packages/learn-github-packages/connecting-a-repository-to-a-package#connecting-a-repository-to-a-container-image-using-the-command-line