docs: add notes on JS options for custom providers #77

	name: Snyk Container

	on:
	push:
	branches: [ "main" ]
	# pull_request:
	# branches: [ "main" ]
	schedule:
	- cron: '18 8 * * 2'

	permissions:
	contents: read

	jobs:
	snyk:
	permissions:
	contents: read
	security-events: write
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
	- name: Build a Docker image
	run: docker build -t michad/tilegroxy .
	- name: Run Snyk to check Docker image for vulnerabilities
	continue-on-error: true
	uses: snyk/actions/docker@d406fd286b663eb8c6f8adcced4f7bcd199c0a3f
	env:
	SNYK_TOKEN: ${{ secrets.SNYK_TOKEN }}
	with:
	image: michad/tilegroxy
	args: --file=Dockerfile
	# Snyk sometimes generates invalid severity scores that tank the upload step. And they're insistent on not fixing the bug. So we need to post-process it to avoid build failures
	# See https://github.com/github/codeql-action/issues/2187 for more context.
	- name: Post-process sarif output
	run: \|
	sed -i 's/"security-severity": null/"security-severity": "0"/g' snyk.sarif
	sed -i 's/"security-severity": "null"/"security-severity": "0"/g' snyk.sarif
	sed -i 's/"security-severity": "undefined"/"security-severity": "0"/g' snyk.sarif
	- name: Upload result to GitHub Code Scanning
	uses: github/codeql-action/upload-sarif@23acc5c183826b7a8a97bce3cecc52db901f8251 # v3.25.10
	with:
	sarif_file: snyk.sarif

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