feat: miscellaneous changes

[grunweg]

• add an anchor to each table: this allows jumping directly to each section This is useful if linkifiers want to link to certain sections. A future PR could also add navigation facilities at the top of the page. Both ideas are left as future work.
• Rename a misleading variable (likely the result of copy-paste).
• Note when the dashboard was last updated: that's one of my first questions when looking at it :-)

Mostly addresses #4 (it does not look at the PR titles).

[grunweg]

Extracted from #14; these changes should be uncontroversial.