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.

---------

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

core/src/plugins-helper.js

@@ -0,0 +1,26 @@
+import { defineProperty } from "polyscript/exports";
+
+// helper for all script[type="py"] out there
+const before = (script) => {
+    defineProperty(document, "currentScript", {
+        configurable: true,
+        get: () => script,
+    });
+};
+
+const after = () => {
+    delete document.currentScript;
+};
+
+// common life-cycle handlers for any node
+export default async (main, wrap, element, hook) => {
+    const isAsync = hook.endsWith("Async");
+    const isBefore = hook.startsWith("onBefore");
+    // make it possible to reach the current target node via Python
+    // or clean up for other scripts executing around this one
+    (isBefore ? before : after)(element);
+    for (const fn of main(hook)) {
+        if (isAsync) await fn(wrap, element);
+        else fn(wrap, element);
+    }
+};