chore(core): update moonbeam url (gakonst#1228)

Author: mattsse

ethers-core/src/utils/moonbeam.rs

@@ -4,7 +4,7 @@ use std::collections::BTreeMap;
 
 use k256::SecretKey;
 
-/// Returns the private developer keys <https://docs.moonbeam.network/snippets/code/setting-up-node/dev-accounts/>
+/// Returns the private developer keys <https://docs.moonbeam.network/builders/get-started/networks/moonbeam-dev/#pre-funded-development-accounts>
 pub fn dev_keys() -> Vec<SecretKey> {
     MoonbeamDev::default().into_keys().collect()
 }