removed redundant default yaml output and adjusted docs to reflect new changes

[ehearneRedHat]

In relation to #75 .

What:

• removed redundant default yaml output and adjusted docs to reflect new changes

Verify:

To verify, compile binary from root directory on this branch using go build and run the following commands:

./kuadrantctl generate gatewayapi httproute --help
./kuadrantctl generate kuadrant authpolicy --help
./kuadrantctl generate kuadrant ratelimitpolicy --help

Verify that there is no longer any redundant yaml output as mentioned in #75 . Also verify that the docs changed don't mention the redundant default yaml ouput anymore.

[ehearneRedHat]

@eguzki feel free to review when you have the chance :)