docs: update get_balance docs (#938)

* docs: update get_balance docs

* Update crates/provider/src/provider/trait.rs

Co-authored-by: Oliver <onbjerg@users.noreply.github.com>

---------

Co-authored-by: Oliver <onbjerg@users.noreply.github.com>

crates/provider/src/provider/trait.rs

@@ -248,7 +248,9 @@ pub trait Provider<T: Transport + Clone = BoxTransport, N: Network = Ethereum>:
         RpcWithBlock::new(self.weak_client(), "eth_getAccount", address)
     }
 
-    /// Gets the balance of the account at the specified tag, which defaults to latest.
+    /// Gets the balance of the account.
+    ///
+    /// Defaults to the latest block. See also [`RpcWithBlock::block_id`].
     fn get_balance(&self, address: Address) -> RpcWithBlock<T, Address, U256> {
         RpcWithBlock::new(self.weak_client(), "eth_getBalance", address)
     }