The chat quoting mechanism will need to be able to generate
markdown for all kinds of uploads. The UploadMarkdown class
was missing generation for video and audio uploads. This
commit adds that in, and also expands the server-side regex
recognition of FileHelper types to match those in uploads.js,
and adds a spec for UploadMarkdown
Zeitwerk simplifies working with dependencies in dev and makes it easier reloading class chains.
We no longer need to use Rails "require_dependency" anywhere and instead can just use standard
Ruby patterns to require files.
This is a far reaching change and we expect some followups here.
