add README

Author: flyq

README.md

@@ -1,5 +1,9 @@
 # ecdsa_motoko
 
+Just for learning, Do not use in production environment.
+
+Without performance optimization, verifying two signatures in one call will cause the instruction limit to be exceeded.
+
 ```bash
 # Starts the replica, running in the background
 dfx start --background

src/ecdsa_motoko_backend/main.mo

@@ -41,12 +41,6 @@ actor {
     let s1 = 0x1878DBC4684DE3A63A5975325B467CDBA846B24D949322016FE4C8FD2C0862A1;
     assert secp256r1.verify_ecdsa(pub, msg_hash1, r1, s1);
 
-    // let msg_hash2 = 0x0F1AE6C77FEE73F3AC9BE1217F50C576C07D7E5FAA0E178A232DD33D09FF2CDE;
-    // let r2 = 0xB9201D2D40D63EB41D934C9D45280837CA09B03C4E063946CAA06EABEAACB944;
-    // let s2 = 0xBA69F449ED11E3677AB37367D99EC3B399A006FE875941F5DA57156A8FE9C8E0;
-
-    // assert secp256r1.verify_ecdsa(pub, msg_hash2, r2, s2);
-
     return true;
   };