GitLab

These are derived from the git history, so some aren't exactly
right (e.g., modified dates from a commit where we just added/removed a
tag or something), but close enough and a good first pass.

Depending on git info to generate the modified date is kinda convenient
in that I don't have to maintain the date manually, but can be
wrong (e.g., do something in git that touches the file, like moving it,
but doesn't meaningfully change it's content) and means there's a
dynamic element to building the site (generating the site depends on
information outside of the source files), which complicates CI.

So I want to move the modified date into the YAML front matter of the
content itself. Picking up the "published" date as well for good
measure. It's not currently used by pages and posts get it from the file
name, but may be utilized in the future and enables specifying the exact
time I consider a post published (if I want).

Correct/complete site generation can now driven entirely by nix (e.g.,
by Hydra). Downside is now the content derivation depends on the state
of the git directory, which changes with every commit, even it if it
doesn't impact anything with content generation. Site generation will
run on every commit.

I don't think this is the way to go long-term, but it does work.

Also update lambda to allow cross-origin access to matrix client config.

Node.js 8.x is EOL.

Doh, Hakyll's dependency stuff knows to load the `/assets/css/clay.css`
id the Clay compilation stuff makes even though we don't actually write
a file to the filesystem with that name.

Interesting that I haven't noticed this bug before, guess there's almost
only one reference to the versioned file in each file.

Don't have to rebuild the site executable for every CSS change so
`watch` works better.