Define project slug in Tenderly configuration

The hardhat tenderly plugin doesn't work perfectly yet
(Tenderly/hardhat-tenderly#20),
but we're aready defining the project slug we created in Tenderly to be
used here.

Author: michalinacienciala

hardhat.config.ts

@@ -48,7 +48,7 @@ const config: HardhatUserConfig = {
   },
   tenderly: {
     username: "thesis",
-    project: "",
+    project: "thesis/threshold-network",
   },
   etherscan: {
     apiKey: process.env.ETHERSCAN_API_KEY,