[stable-4.2] Rename master to main in workflows and docs #7512

	name: "PR checks"

	on:
	pull_request:
	branches: [ 'main', 'stable-*' ]

	jobs:
	pr-checks:
	runs-on: ubuntu-latest
	steps:

	- name: "Checkout ansible-hub-ui (${{ github.ref }})"
	uses: actions/checkout@v3

	- name: "Install node 16"
	uses: actions/setup-node@v3
	with:
	node-version: '16'
	cache: 'npm'

	- name: "Checks"
	run: \|
	# fail if npm install had to change package-lock.json
	npm install
	git diff --exit-code package-lock.json

	# same in test/
	pushd test/
	npm install
	git diff --exit-code package-lock.json
	popd

	# run linters
	npm run lint

	merge-commits:
	runs-on: ubuntu-latest
	steps:

	# need to checkout out head, the merge commit won't have any merges in history
	# also need more than 1 commit, assuming no PR will have more than 128
	- name: "Checkout ansible-hub-ui HEAD"
	uses: actions/checkout@v3
	with:
	fetch-depth: 128
	ref: ${{ github.event.pull_request.head.sha }}

	- name: "Ensure no merge commits"
	run: \|
	# fail on merge commits in the PR
	# since squash&merge doesn't create merge commits,
	# and the last non-squash merges were in Jul 2019,
	# we can just look for any merge commits since 2020
	count=`git log --min-parents=2 --since 2020-01-01 \| tee /dev/stderr \| wc -l`
	[ "$count" = 0 ]

Provide feedback