docs(changeset): Fix issue with manyToMany behavior warnings #1372

Job	Run time
@dataplan/pg tests / build (12, 20.x)	3m 35s
PostGraphile mutation tests / build (12, 20.x)	3m 41s
PostGraphile mutation tests (exported as graphql-js) / build (12, 20.x)	9m 54s
PostGraphile mutation tests (exported as typeDefs) / build (12, 20.x)	8m 3s
PostGraphile polymorphic query tests / build (12, 20.x)	3m 13s
PostGraphile polymorphic query tests (exported as graphql-js) / build (12, 20.x)	7m 39s
PostGraphile polymorphic query tests (exported as typeDefs) / build (12, 20.x)	6m 33s
PostGraphile v4 queries tests (exported as graphql-js) / build (12, 20.x)	17m 10s
PostGraphile v4 queries tests / build (12, 20.x)	4m 10s
PostGraphile v4 queries tests (exported as typeDefs) / build (12, 20.x)	14m 20s
Small package tests / build (12, 20.x)	3m 11s
PostGraphile schema tests / build (12, 20.x)	6m 29s
	1h 27m 58s

Provide feedback