Format/slightly modernize the JS (#345)

* add basic JS tooling

* fix accidental uses of global variables

* auto-format

* add and fix a couple more standard lint rules

* remove useless return false from settimeout callbacks

* document JS contributing

* fix whitespace in package.json

* add JS stuff to codespell skiplist

* codespell take two

* update github action and add comments about duplicated logic

.github/workflows/lint_python.yml

@@ -6,11 +6,13 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2
+      # note: this logic is duplicated in the `validate` function in ./deploy.sh
+      # if you update this file, you should update that as well
       - run: pip install --upgrade pip wheel
       - run: pip install bandit black codespell flake8 flake8-bugbear
                          flake8-comprehensions isort
       - run: black --check --diff --line-length 79 .
-      - run: codespell
+      - run: codespell --skip="./.git,./package.json,./package-lock.json,./node_modules"
       - run: flake8 . --count --max-complexity=10 --max-line-length=79
                       --show-source --statistics
       - run: isort --check-only --line-length 79 --profile black .