Initial commit: add .gitignore and README

smart_contracts/contracts/Counter.sol

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.10;
+contract Counter {
+    int private count = 0;
+    function incrementCounter() public {
+        count += 1;
+    }
+    function decrementCounter() public {
+        count -= 1;
+    }
+    function getCount() public view returns (int) {
+        return count;
+    }
+}