Added @mdx_str version to address issue #5.

[snoeyink]

Created @mdx_str from @markdown by using @htl_str in place of @htl. This means that one need not escape \ in mdx" ``\LaTeX``", for example. Factored out _make_cm_parser()
Considerations:

1. This will work best after pull HypertextLiteral#30, which aims to remove the @htl_str behavior of interpolating (escaped) \$, so it matches @htl and cm" " behavior.
2. I factored out the _make_cm_parser so mdx" " and @markdown would have consistent options; you may be able to think of a reason that they should parse differently.

Attached is a Pluto notebook demonstrating some behaviors of @mdx(" "), mdx" ", cm" ", and htl" "
mdxTesting2.zip

[github-actions]

Try this Pull Request!

Open Julia and type:

julia> import Pkg
julia> Pkg.activate(temp=true)
julia> Pkg.add(url="https://github.com/snoeyink/MarkdownLiteral.jl", rev="main")
julia> using MarkdownLiteral

Or run this code in your browser:

[snoeyink]

Actually, you also want my version of HypertextLiteral, which I'm guessing from the bot response that you could get this way:

julia> import Pkg
julia> Pkg.activate(temp=true)
julia> Pkg.add(url="https://github.com/snoeyink/HypertextLiteral.jl", rev="main")
julia> using HypertextLiteral
julia> Pkg.add(url="https://github.com/snoeyink/MarkdownLiteral.jl", rev="main")
julia> using MarkdownLiteral

[fonsp]

#5