Fix 111: Package comments are now split correctly from the rest of the comments

[dlsniper]

This allows package comments to be generated following the rules here: https://staticcheck.io/docs/checks#ST1000

Before:

//  mockgen -destination demo/mock.go -package demo . Demoer
//
// Package demo is a generated GoMock package.
package demo

After:

//  mockgen -destination demo/mock.go -package demo . Demoer
//

// Package demo is a generated GoMock package.
package demo