Clarify how built-in modules are standardized (#7387)
Clarify how built-in modules are standardized (#7387)

Also, emphasize that they're currently in an experimental phase, and
soften the language around deploying them today.
myakura/WebFundamentals,myakura/WebFundamentals,lucab85/WebFundamentals,google/WebFundamentals,myakura/WebFundamentals,samdutton/WebFundamentals,lucab85/WebFundamentals,myakura/WebFundamentals,samdutton/WebFundamentals,google/WebFundamentals,lucab85/WebFundamentals,samdutton/WebFundamentals,samdutton/WebFundamentals,lucab85/WebFundamentals,google/WebFundamentals,google/WebFundamentals