v1.2.1: Add examples to godoc

Add test examples for godoc

v1.2.0: Fixes CamelCase() for an already camelCased input

Mark letter case changes to fix "camelCaseText" input

v1.1.0: Implement kebab-case

textcase.CamelCase() // camelCase
textcase.PascalCase() // PascalCase
textcase.SnakeCase() // snake_case
textcase.KebabCase() // kebab-case

v1.0.0: Stable release of textcase pkg

textcase.CamelCase() // camelCase
textcase.PascalCase() // PascalCase
textcase.SnakeCase() // snake_case