update project files (#5457)

* update pre-commit hook
* upgrade pip with venv
* update description and version
* show url in publish environment
* update versions
* update versions, separate typing job
* use dependabot grouped updates
  ignore upload/download-artifact until slsa updates
* use sphinx.ext.extlinks instead of sphinx-issues
* update dev dependencies
* update editorconfig
* update gitignore
* update .readthedocs.yaml
* license is txt, readme is md
* update pyproject.toml
  add typed classifier
  add pyright config
  simplify urls
* tox builds docs in place
* update min test py version
* add tox env to update all dev dependencies
* update issue and pr templates
* rename security docs page to not conflict with org policy file
* simplify matrix

.github/ISSUE_TEMPLATE/config.yml

@@ -1,11 +1,11 @@
 blank_issues_enabled: false
 contact_links:
   - name: Security issue
-    url: security@palletsprojects.com
-    about: Do not report security issues publicly. Email our security contact.
+    url: https://github.com/pallets/flask/security/advisories/new
+    about: Do not report security issues publicly. Create a private advisory.
   - name: Questions
-    url: https://stackoverflow.com/questions/tagged/flask?tab=Frequent
-    about: Search for and ask questions about your code on Stack Overflow.
-  - name: Questions and discussions
+    url: https://github.com/pallets/flask/discussions/
+    about: Ask questions about your own code on the Discussions tab.
+  - name: Questions on
     url: https://discord.gg/pallets
-    about: Discuss questions about your code on our Discord chat.
+    about: Ask questions about your own code on our Discord chat.