All error returned by `pallet` macro should have an error number linking to some full description.

[gui1117]

Similarly to rustc --explain E0308 I think we can have a number for each error returned by the pallet macro.
And document the error with examples somewhere.

For example instead of:

error: Invalid pallet::error, expected item enum
  --> $DIR/error_wrong_item.rs:19:2
   |
19 |     pub struct Foo;
   |     ^^^

we should have:

error: Invalid pallet::error, expected item enum. Pallet error 21 see more at https://...#21
  --> $DIR/error_wrong_item.rs:19:2
   |
19 |     pub struct Foo;
   |     ^^^

[stale]

Hey, is anyone still working on this? Due to the inactivity this issue has been automatically marked as stale. It will be closed if no further activity occurs. Thank you for your contributions.

[gui1117]

still sensible to me