v3.15.0b2
[3.15] gh-149861: Fix rule in match statement `case_block` PEG grammar (GH-149908)
[3.15] gh-150403: Document frozendict in language reference Mappings section (GH-150404) (GH-150590)
gh-135944: Add a "Runtime Components" Section to the Execution Model Docs (gh-135945)
[3.15] gh-141984: Reword docs on "enclosed" atom grammar (GH-148622) (GH-150552)
gh-143054: Disallow non-top-level Cut for now (GH-143622)
[3.15] gh-148672: Document namespace subpackages inside regular packages (GH-150056) (#150729)
Merge from 3.2: remove unneeded "Release" and "Date" markers from index pages.
gh-135676: Lexical analysis: Reword String literals and related sections (GH-135942)
Docs: Fix a typo in the 'Non-ASCII characters in names' section (#148043)
gh-137337: Clarify import statement namespace binding (GH-144607)
gh-130587: Add hand-written docs for non-OP tokens (GH-130588)