Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

vendor/clap_derive/src/utils/mod.rs

@@ -0,0 +1,13 @@
+pub mod error;
+
+mod doc_comments;
+mod spanned;
+mod ty;
+
+pub use doc_comments::extract_doc_comment;
+pub use doc_comments::format_doc_comment;
+
+pub use self::{
+    spanned::Sp,
+    ty::{inner_type, is_simple_ty, sub_type, subty_if_name, Ty},
+};