Add Giscus widget to documentation #1379

Job	Run time
sdist	52s
mypy	24s
ruff	7s
parse_sdl (macos-latest, 3.2.16)	35s
parse_sdl (windows-latest, 3.2.16)	39s
build-macos (cp310-*_universal2)	2m 25s
tox (ubuntu-latest)	2m 4s
build-macos (pp310-*)	5m 3s
pyodide	2m 37s
test-docs	1m 49s
linux-wheels (aarch64, cp310-manylinux*)	4m 18s
linux-wheels (x86_64, cp310-manylinux*)	4m 7s
build (windows-latest, 3.10, x86)	3m 36s
linux-wheels (x86_64, pp310-manylinux*)	3m 49s
build (windows-11-arm, 3.11, arm64)	4m 19s
build (windows-latest, 3.10, x64)	2m 53s
build (windows-latest, pypy-3.10, x64)	3m 52s
linux-wheels (aarch64, pp310-manylinux*)	3m 41s
build (ubuntu-latest, 3.10, x64)	3m 55s
build (ubuntu-latest, pypy-3.10, x64)	3m 6s
publish	0s
	54m 11s

Provide feedback