Rename #[doc] attributes to #[description] for groups (#1245)

This copies the rename action for the `#[doc]` attribute from commands to groups, allowing a user to describe a group with documentation comments.

Author: arqunis

command_attr/src/lib.rs

@@ -628,7 +628,10 @@ pub fn group(attr: TokenStream, input: TokenStream) -> TokenStream {
                 options.prefixes = vec![propagate_err!(attributes::parse(values))];
             },
             "description" => {
-                let arg: String = propagate_err!(attributes::parse(values));
+                let mut arg: String = propagate_err!(attributes::parse(values));
+                if arg.starts_with(' ') {
+                    arg.remove(0);
+                }
 
                 if let Some(desc) = &mut options.description.0 {
                     use std::fmt::Write;

command_attr/src/structures.rs

@@ -581,6 +581,8 @@ impl Parse for GroupStruct {
     fn parse(input: ParseStream<'_>) -> Result<Self> {
         let mut attributes = input.call(Attribute::parse_outer)?;
 
+        util::rename_attributes(&mut attributes, "doc", "description");
+
         let cooked = remove_cooked(&mut attributes);
 
         let visibility = input.parse()?;