refactor: rename elm-quote crate to genco-extra

I want to add quoting rules for nginx config language. I decided it
would be better to group all the language definitions in the same crate.

src/exec/fixtures/astrid_pages.rs

@@ -1,5 +1,5 @@
 use crate::exec::astrid_pages::OutputType;
-use elm_quote::Tokens;
+use genco_extra::elm::Tokens;
 use genco::tokens::quoted;
 use serde::{Deserialize, Serialize};
 

src/exec/fixtures/css_in_elm.rs

@@ -1,4 +1,4 @@
-use elm_quote::Tokens;
+use genco_extra::elm::Tokens;
 
 pub(crate) fn generate(source_checksum: u64, entrypoint: &elmi::Global) -> (String, String) {
     let tokens: Tokens = genco::quote! {