This change introduces a new command to `@TheRespectPanda` bot,
allowing him to dispatch the ci-perf.yml workflow benchmarks for
a pull request.
Initially, the bot will just trigger it and return the workflow
run URL for manual inspection. Future iterations on this feature
could then grab the benchmark results and update the comment.
Includes a basic bot workflow that just answers "pong" to ping
requests, includes a help message and ignores invalid commands.
This is the minimum feature that exercises token access, non
recursive comments (answering to its own pong) and so on.
