v2.2.0dev0
DOC: Gitpod documentation (#49642)
DOC Change slack invitation from email to link (#52014)
DOC: Simplify contributing intro (#54220)
TST: Use pytest or assert_produces_warnings instead of catch_warnings (#54390)
Change Naming Scheme of Series (#53312)
DOC: change code block for black (#54146)
DOC: Adjust build command for building with meson (#53392)
Contributor Docs: update gitpod docs and small fix (#54292)
DOC: Add user guide section about copy on write (#51454)
Improved documentation for extension development (#53380)
ENH: allow JSON (de)serialization of ExtensionDtypes (#44722)
DOC: Move ecosystem.rst to getting started section (#52944)
DOC: Remove roadmap.rst in favor of the website roadmap (#54283)
DEPR: subclassing Index (#52186)
DOCS: clarify self-merging and needs-triage (#54286)
DOC: Add security policy (#54060)