Add groups to repo justfile

[neunenak]

This commit adds the recipes in the repo's own justfile to several recipe groups.

[neunenak]

I thought it would be nice if the just project's own justfile exhibited groups and had more documentation of the recipes. I picked some group names that I thought made sense, don't feel very strongly about the exact names or categorization scheme.

[casey]

Let's just do groups first, since it's less to nitpick.

What do you think of these groups? I'd like to keep the names short. I also like single quotes, since they don't require hitting the shift key to type. (I also just merged #2367, which nuked a bunch of old recipes, so some of the following are gone.)

[group: 'dev']
watch
push
pr
done
install-dev-deps
replace
convert-integration-test

[group: 'test']
test
filter
test-completions
test-bash-completions
test-release-workflow

[group: 'check']
ci
lint
fuzz
shellcheck
check
outdated
clippy
forbid
build-book

[group: 'misc']
run
build
fmt
install
sloc

[group: 'doc']
man
view-man
render-readme
watch-readme

[group: 'release']
update-changelog
update-contributors
publish
readme-version-notes

[group: 'demo']
test-quine
quine
polyglot
pwd

[neunenak]

yeah those groups seem good to me