Refactor repository. Fixes #2161 (#2192)

* Remove duplicate LICENSE.
* Remove un-userd pyscript.sw directory and its content.
* Remove ReadTheDocs settings (unused).
* Remove un-used pyproject.toml
* Remove now unused CHANGELOG. Changes now tracked via release notes on GitHub.
* Updated / cleaned release page template and associated GH actions.
* Update prettierignore to remove un-needed refs.
* Move troubleshooting into correct README.
* Add reason for the index.html
* Rename the "pyscript.core" directory to "core".
* Update PR template because CHANGELOG is no longer used.
* Codespell configuration in pyproject.toml.
* Update pyscript.core -> core in .githubignore
* Remove test-results/.last-run.json. This should be ignored by git.
* Pin nodejs version.

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

core/tests/javascript/config-url/src/test.py

@@ -0,0 +1,8 @@
+from pyscript import RUNNING_IN_WORKER, document
+
+classList = document.documentElement.classList
+
+if RUNNING_IN_WORKER:
+    classList.add("worker")
+else:
+    classList.add("main")