OperatorSDK generated files with [.osdk.yaml] file type

[jefflill]

What would you think of having the OperatorSDK generated file have a unique file type like .osdk.yaml, ogen.yaml, or something?

The idea here is to make it easy to .gitignore all of these files. Right now, we're explicitly ignoring these by path, but that's fragile because it's very possible to to add a new RBAC conditions that will generate new files that will probably get tracked by Git until we figure that out and have to manually ignore them,

[marcusbooyah]

I changed the default extension to .g.yaml for now.