feat: support doc comments for functions args and validator params

- Add support to the formatter for these doc comments
- Add a new field to `Arg` `doc: Option<String>`
- Don't attach docs immediately after typechecking a module
  - instead we should do it on demand in docs, build, and lsp
  - the check command doesn't need to have any docs attached
  - doing it more lazily defers the computation until later making
    typechecking feedback a bit faster
- Add support for function arg and validator param docs in
  `attach_module_docs` methods
- Update some snapshots
- Add put_doc to Arg

closes #685

crates/aiken-lsp/src/server/lsp_project.rs

@@ -42,7 +42,7 @@ impl LspProject {
 
         let modules = self.project.modules();
 
-        for module in modules.into_iter() {
+        for mut module in modules.into_iter() {
             let path = module
                 .input_path
                 .canonicalize()
@@ -55,6 +55,8 @@ impl LspProject {
 
             let source = SourceInfo { path, line_numbers };
 
+            module.attach_doc_and_module_comments();
+
             self.sources.insert(module.name.to_string(), source);
             self.modules.insert(module.name.to_string(), module);
         }