doc comment on payer and lamports

Author: rustopian

programs/system/src/instructions/create_account_allow_prefund.rs

@@ -31,6 +31,9 @@ pub struct CreateAccountAllowPrefund<'a> {
 
 impl<'a> CreateAccountAllowPrefund<'a> {
     #[inline(always)]
+    /// Creates a new CreateAccountAllowPrefund instruction with the minimal balance required
+    /// for the account. The caller must provide a `payer` if the account needs lamports;
+    /// otherwise, the resulting instruction will fail downstream.
     pub fn with_minimal_balance(
         payer: Option<&'a AccountView>,
         to: &'a AccountView,