gas-report readme

packages/gas-report/README.md

@@ -1 +1,26 @@
 # Gas Report
+
+Gas reporter for specific lines within forge tests
+
+Add some reports to your forge tests
+
+```solidity
+import { Test } from "forge-std/Test.sol";
+import { GasReporter } from "@latticexyz/gas-report/src/GasReporter.sol";
+
+contract ExampleTest is Test, GasReporter {
+  function testGas() public {
+    startGasReport("Describe what is being gas-reported on");
+    // do something here
+    endGasReport();
+  }
+}
+```
+
+Then use the cli command to run tests and save the report:
+
+```console
+pnpm mud-gas-report --save gas-report.json
+```
+
+Run `pnpm mud-gas-report --help` for more details.