Add read/write connections to new features in 5.0

Author: othercorey

en/appendices/5-0-migration-guide.rst

@@ -301,6 +301,8 @@ Core
 Database
 --------
 
+- ``ConnectionManager`` now supports read and write connection roles. Roles can be configured
+  with ``read`` and ``write`` keys in the connection config that override the shared config.
 - ``Query::all()`` was added which runs result decorator callbacks and returns a result set for select queries.
 - ``Query::comment()`` was added to add a SQL comment to the executed query. This makes it easier to debug queries.
 - ``EnumType`` was added to allow mapping between PHP backed enums and a string or integer column.