add ability to manually name enum variants, currently it is bound to `kebab-case`

[twop]

this what I currently have in mind

#[derive(knus::Decode, Debug)]
enum Text {
    #[knus(name="Raw")]
    Raw(Raw),

    #[knus(name="CallFunc")]
    CallFunc(Call),
}

This is in part inspired by zellij style of APIs, where commands are using pascal case: https://zellij.dev/documentation/keybindings-possible-actions

Note that if my understanding is correct then my assumption that it will be possible to name two variants the same, and thus enabling patterns like this:

// note that "text" node should have either one argument or a nested node only
// thus enum might be a good data structure for that 

text "raw text"

text {
  call "funcName"
}

although, no promises that the last one will work, depends greatly on the code structure.

[twop]

will probably take a stub at this myself tonight