Replace "External accounts" with "Externally-owned accounts" for accuracy

Author: codersjj

docs/introduction-to-smart-contracts.rst

@@ -338,7 +338,7 @@ Accounts
 ========
 
 There are two kinds of accounts in Ethereum which share the same
-address space: **External accounts** that are controlled by
+address space: **Externally-owned accounts** that are controlled by
 public-private key pairs (i.e. humans) and **contract accounts** which are
 controlled by the code stored together with the account.