docs: Improve quickstart guide formatting and environment setup clarity (#1508)

* Update quickstart.md

* Update quickstart.md

* Update quickstart.md

* Update quickstart.md

---------

Co-authored-by: wbnns <hello@wbnns.com>

Author: DeVikingMark

apps/base-docs/docs/building-with-base/quickstart.md

@@ -113,6 +113,10 @@ Never share or commit your private key. Always keep it secure and handle with ca
 
 Now that your environment is set up, let's deploy your contracts to Base Sepolia.
 
+:::warning
+Before proceeding with deployment, make sure you have enough test ETH in your wallet on Base Sepolia. You can get test ETH from the faucets mentioned earlier in this guide.
+:::
+
 1. Use the following command to compile and deploy your contract
 
 ```bash