fix: issues with the given samples

[Shabirmean]

• Running go mod init without. a module name throws an error
• The kubeObject.IsGVK function has three arguments group, version, kind string

[yuwenma]

Thank you @Shabirmean, one minor comment.

[Shabirmean]

Thank you @Shabirmean, one minor comment.

Thank you for the quick review @yuwenma. Sorry, but I am not seeing any comments. Did you want me to look into something?

[yuwenma]

May the "without. a module name throws an error" caused by missing ln 32?

Since we need to run go mod tidy, it's better to cd into the ${FUNCTION_NAME}. Otherwise we need to add ln 32 after go mod init ${FUNCTION_NAME}.

[Shabirmean]

I've tried both ways:

• First cd ${FUNCTION_NAME} and then do go mod init
• First go mod init

In both cases I get the error

go: cannot determine module path for source directory /tmp/kpt/set-annotation (outside GOPATH, module path must be specified)

Example usage:
	'go mod init example.com/m' to initialize a v0 or v1 module
	'go mod init example.com/m/v2' to initialize a v2 module

Run 'go help mod init' for more information.

Sorry, I am quite new to Go and not completely sure if I am missing some specific setup in my environment.