Fix docs pipeline, make docs tests easier to run locally and on different OSes (#1554)

* update docs pipeline to use poe task runner

* move npm dependency into package.json file instead of hardcoding into pipeline

* replace nix-specific call with python version (for windows compat)

* update commands to use python for win compat

* update lock file

* change deps to take out xq and use xmltodict instead

* move script tasks from pyproject into new tasks.py

* run linting on new tasks.py file

* fix typo

* clean up pyproject to make valid toml

* update docs with correct task runner command

* use npx in case node_modules/.bin isn't in the path

* Run pa11y-ci in cross-platform manner (works on Windows)

* Add node_modules to .gitignore

* clean up poe alias

Co-authored-by: Micah Jerome Ellison <micah.jerome.ellison@gmail.com>

package.json

@@ -0,0 +1,5 @@
+{
+  "devDependencies": {
+    "pa11y-ci": ">=3.0.1"
+  }
+}