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

deploy.sh

@@ -82,10 +82,12 @@ function validate {
 
     echo "run validate on $check_path"
 
+    # note: this logic is duplicated in the `./github/workflows/lint_python.yml` config
+    # if you update this file, you should update that as well
     echo "running black"
     black --diff --color --check -l 79 "$check_path"
     echo "running codespell"
-    codespell --skip="./.git" "$check_path"
+    codespell --skip="./.git,./package.json,./package-lock.json,./node_modules" "$check_path"
     echo "running flake8"
     flake8 "$check_path" --count --max-complexity=10 --max-line-length=79 \
         --show-source --statistics