[DOCS] pg_inherits documentation clarification

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/9.6/static/catalog-pg-inherits.html
Description:

The pg_inherits documentation
(https://www.postgresql.org/docs/current/static/catalog-pg-inherits.html)
says that "There is one entry for each direct child table in the database."
This seems subtly inaccurate/misleading in the case where a single child
table has two parents.  In that case, there is one child table, but two
entries.  Perhaps it would be better phrased as saying that "there is one
entry for each direct child table *relationship* in the database", or
something to that effect.