add readme to gda example

projects/gda-advertisement-auction/README.md

@@ -0,0 +1,16 @@
+# Welcome to the Advertisement Auction
+
+### A basic example to get you started with the Superfluid's Distributions (General Distribution Agreement)
+
+To get started with the updated version:
+
+1. Navigate to the `foundry-tests`folder
+    * `cd projects/gda-advertisement-auction/foundry-tests`
+2. Create a .env file or simple export the environment variable RPC URL necessary for the Polygon Mumbai fork:
+    * `export MUMBAI_RPC_URL=https://rpc-mumbai.maticvigil.com`
+    Make sure to use a un RPC URL that is functional. Check [Chainlist](https://chainlist.org/chain/80001) for more URLs.
+3. Install dependencies with specific commands:
+    * `forge install superfluid-protocol-monorepo=https://github.com/superfluid-finance/protocol-monorepo@dev --no-commit`
+    * `forge install https://github.com/OpenZeppelin/[email protected] --no-commit`
+4. Compile the contracts with `forge build`.
+5. Run the test suite with `forge test`.