add CDK testnet info

Author: kmurphypolygon

docs/cdk/get-started/connect-testnet.md

@@ -0,0 +1,15 @@
+## Stavanger
+
+The [CDK Stavanger testnet](https://polygon.technology/cdk-stavanger-testnet) is a validium testnet based on Sepolia.
+
+- Add the RPC network details to your wallet by navigating to the add network input and entering the data as given in the table below.
+- Use the faucet to get test ETH.
+- Bridge assets from Sepolia to Stavanger using the bridge.
+- Confirm your transactions with the block explorer.
+
+| Use case | URL | Usage |
+| ------- | ----------- | --------- | 
+| JSON RPC | https://sn2-stavanger-rpc.eu-north-2.gateway.fm | Make remote procedure calls to the CDK testnet. |
+| Faucet | https://sn2-stavanger-faucet.eu-north-2.gateway.fm | Get testnet tokens. |
+| Bridge | https://sn2-stavanger-bridge.eu-north-2.gateway.fm | Bridge tokens from Sepolia. |
+| Block explorer | https://sn2-stavanger-blockscout.eu-north-2.gateway.fm | Confirm transactions with the explorer. |

mkdocs.yml

@@ -43,6 +43,7 @@ nav:
       - CDK: cdk/index.md
       - Overview: cdk/overview.md
       - Get started:
+        - Connect testnet: cdk/get-started/connect-testnet.md
         - Quickstart:
           - Validium: cdk/get-started/quickstart-validium.md
           - Rollup: cdk/get-started/quickstart-rollup.md
@@ -58,7 +59,6 @@ nav:
         - Rollup: cdk/concepts/rollup.md
         - Validium: cdk/concepts/validium.md
         - Data availability: cdk/concepts/dac.md
-     # - API/SDK:
       - Additional resources:
         - CDK repos: cdk/resources/cdk-repo-reference.md
   - zkEVM: