tools/setup/generate_zulip_bots_static_files now starts off by
deleting static/generated/bots/ (if it hasn't been removed already)
so that outdated static files from older versions of the zulip_bots
package don't supress errors in the main repo that would otherwise
break.
For more info, see #7542Fixes: #7542.
This commit implements support for copying over static files
for all bots in the zulip_bots package to
static/generated/bots/ during provisioning. This directory
isn't tracked by Git. This allows us to have access to files
stored in an arbitrary zulip_bots package directory somewhere
on the system. For now, logo.* and doc.md files are copied over.
This commit should act as a starting point for extending our
macro-based Markdown framework to our bots/API packages'
documentation and eventually rendering these static files
alongside our webhooks' documentation.