ci: GitHub pr/issue dashboard

[dougch]

Security issue notifications

If you discover a potential security issue in s2n-quic we ask that you notify
AWS Security via our vulnerability reporting page. Please do not create a public github issue.

Problem:

Similar to s2n-tls, we'd like a page with useful saved GitHub queries to speed up responding to issues and PRs by humans.

Solution:

Using a static page generator, we can publish a simple dashboard to the gh-pages branch, under /dashboard, to not interfere with the existing documents there.

Example s2n-tls dashboard action

Requirements / Acceptance Criteria:

The top need is a search link to external PRs and Issues that need comment or labeling by a human.
After that, variations on "stale": no review, no responses, no updates, etc...

Out of scope: