Restore "Sticky Issues Header" feature #2280

$ git log -S'/* Sticky table header on issues list */' --pretty=format:'%h %an -- %s -- %ad'
a9ec680 Waseem Dahman -- Fix sticky file header tooltips (#1581) -- 2018-11-06 17:43:48 +0200
dd8760b Tom Moor -- 📌Sticky Issues Header (#1311) -- 2018-05-10 20:13:57 +0300

a9ec6800cff605ca6c314b6ea427fccf5795b6e5 combined this and the sticky file headers features together, and changed the comment from /* Sticky table header on issues list */ to /* Sticky file and table headers */

$ git log -S'/* Sticky file and table headers */' --pretty=format:'%h %an -- %s -- %ad'
76cc04d Federico Brigante -- Drop feature `make-headers-sticky` -- 2019-03-18 19:18:55 +0200
a9ec680 Waseem Dahman -- Fix sticky file header tooltips (#1581) -- 2018-11-06 17:43:48 +0200

76cc04d4b69974ce4aa8c02ed2afedb66ad66cd8 removed both sticky issue list headers and sticky file headers (the latter was implemented by GitHub).

To whoever picks this up, keep in mind that dd8760bf324c665088790df8be37a647882a0d88 (#1311) also had a bugfix commit later: 4f43ef673281ce0dec28a88d7893043fcf1a6ca2 (#1318) And maybe it should have an option to disable - so, have a .tsx file to inject a rgb-sticky-header class, like hide-watch-and-fork-count does.

Excellent! Thank you so much for that!