[Request] Document the outputType parameter in module READMEs

[h6ah4i]

WHAT

Several modules expose an outputType parameter, but it isn’t documented in their READMEs.

WHY

For example, the JDBC sink module doesn’t support the ELEMENT type, which makes it incompatible with the Filter transformer’s default output. As a workaround, users currently have to set the (undocumented) outputType parameter manually.