Check docs and run clippy on PRs (#326)

* Check docs, clippy, test run

* test parallel CI adapted from other package; is it faster?

* Remember to download substrate

* Nightly for cargo fmt

* Standardise CI names

* fix clippy complaints

* Ensure docs are valid and export publicly accessible types

* all-targets clippy, and fix additional lint errors

* newline in ci file

codegen/src/api/storage.rs

@@ -44,7 +44,7 @@ pub fn generate_storage(
     let (storage_structs, storage_fns): (Vec<_>, Vec<_>) = storage
         .entries
         .iter()
-        .map(|entry| generate_storage_entry_fns(&type_gen, &pallet, entry))
+        .map(|entry| generate_storage_entry_fns(type_gen, pallet, entry))
         .unzip();
 
     quote! {