Fix deps for local docs build for Rust 1.75.0 (#2896)

- Fix docs deps build issue
(https://github.com/servo/rust-smallvec/issues/327) (Please forgive me
and LMK if there are processes I need to follow for the bump a dep here
I am not aware of).
- Fix links for `meta_contributing` docs, internal and external.
- `cargo +nightly fmt` for `/docs/...` files

docs/sdk/src/guides/your_first_pallet/mod.rs

@@ -365,7 +365,7 @@ pub mod pallet {
 			// ensure sender has enough balance, and if so, calculate what is left after `amount`.
 			let sender_balance = Balances::<T>::get(&sender).ok_or("NonExistentAccount")?;
 			if sender_balance < amount {
-				return Err("InsufficientBalance".into())
+				return Err("InsufficientBalance".into());
 			}
 			let reminder = sender_balance - amount;