Github verification instructions are unclear.

It says something like "Create a Github gist called `keybase.md` with the following content".

It should probably say "Create a _public_ Github gist with `keybase.md` _as filename_ and empty description with the following content". Also private gists that are converted to public later also seem to fail.

It took multiple attempts to find the correct combination to make Keybase recognize the gist.
Also I think Keybase should detect that _some_ new gist recently appeared and show specific message why verification is failed (i.e. which part of the Gist is malformed).

No repository files or tests are named. Start by locating the GitHub gist verification instructions and the verification flow; clarify the required public gist, filename, and description, then determine whether the separate request for malformed-gist diagnostics is in scope and how completion will be verified.

Written by the indexing model from the issue text.