Priority non-experimental types, properties ahead in markdown and meta schema yaml

[jack-berg]

We have a lot of experimental parts of the schema, which muddy the waters of the (soon to be) stable important bits:

• Users consuming schema-docs.md see a big chunk of experimental types right after ExemplarFilter because that's where lexigraphical sorting puts them.
• Maintainers updating meta_schema_language_{language}.yaml similarly see a big chunk after ExemplarFilter.

This PR adjusts the sorting mechanisms to prioritize stable over experimental, then apply lexographical sorting, for both experimental types and properties. For schema-docs.md, I've split out a new Experimental Types section to further emphasize.

[jack-berg]

All the changes to meta_schema_* files are automatically generated by the small changes in scripts/*.js.