Fix deprecation warnings and update CSS #3503

	# Copyright 2020 The Knative Authors.
	#
	# Licensed under the Apache License, Version 2.0 (the "License");
	# you may not use this file except in compliance with the License.
	# You may obtain a copy of the License at
	#
	# http://www.apache.org/licenses/LICENSE-2.0
	#
	# Unless required by applicable law or agreed to in writing, software
	# distributed under the License is distributed on an "AS IS" BASIS,
	# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	# See the License for the specific language governing permissions and
	# limitations under the License.

	# This file is automagically synced here from github.com/knative-extensions/.github
	# repo by knobots: https://github.com/knative-extensions/knobots and will be overwritten.

	name: Knative Verify

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

	jobs:

	verify:
	name: Verify mkdocs strict
	strategy:
	matrix:
	go-version: [1.16.x]
	platform: [ubuntu-latest]

	runs-on: ${{ matrix.platform }}

	env:
	GOPATH: ${{ github.workspace }}

	steps:
	- uses: actions/checkout@v2
	with:
	fetch-depth: 0

	- name: Set up Python
	uses: actions/setup-python@v2

	- name: Install requirements
	run: python3 -m pip install -r requirements.txt

	- name: Verify MkDocs
	run: mkdocs build --strict

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