enhance connector development to mention gradle considerations

[planetf1]

I believe the issue is in ensuring our connector docs clarify that connectors should not include egeria libraries that are part of base egeria when deployed.

These docs should cater for both maven and gradle, since connector developers may chose to use either (even though our preference has become gradle)

For example when declaring dependencies,

• for gradle, ensure 'compileOnly' is used on any egeria libraries found in the server chassis
• for maven, use provided scope

This is to avoid issues whereby backlevel libraries are introduced into the classpath causing connectors to fail

[planetf1]

I propose we merge and then I will submit a new PR with some additional things I thought of

[planetf1]

I've assigned to myself, as I think there is more I could add.