First beta release of GraphQL-core 3, based on GraphQL.js v14.5.0.

GraphQL-core 3 is the successor to both GraphQL-core 2 and GraphQL-core-next.

In addition to incorporating the latest changes from GraphQL.js (see particularly the list of changes in GraphQL.js v14.5.0), this release also contains the following improvements and changes:

• Features: Support using lazy descriptions for GraphQL types (#58)
• Performance: Add pytest-benchmark and port the benchmarks from GraphQL.js (#55)
• Performance: Use identity instead of hash for caching subfields in collect_subfields (#56)
• Changes: Use FrozenLists in AST nodes (#45)
• Changes: Changed is_nullish() to make it play nice with numpy arrays (#60)
• Bugs: Fixed issue #43 with getting parse_literal via to_kwargs()
• Bugs: Fix hash method for AST nodes (#45)
• Docs: Fix typo in docs for using SDL (#48)
• Docs: Update installation instructions (#50)
• Docs: Run all code snippets as part of the test suite
• Polish: Run type check also for functions without type annotations

Contributors to this release were:

@Cito, @CorrosiveKid, @delyanr, @ktosiek, @mvanlonden, @qqi0O0, @thomascobb

Thanks to everybody who contributed by sending bug reports or pull requests. Please continue to report any problems you find in this beta release, so that these can be fixed in the final v3 release.