mentioned Polygon networks supported by The Graph

Author: alinobrasil

docs/tools/data/thegraph.md

@@ -7,6 +7,12 @@
 
 Getting historical data on a smart contract can be frustrating when building a dapp. [The Graph](https://thegraph.com/) provides an easy way to query smart contract data through APIs known as subgraphs. The Graph’s infrastructure relies on a decentralized network of indexers, enabling your dapp to become truly decentralized.
 
+The Graph supports:
+ - Polygon Mainnet
+ - Polygon zkEVM Mainnet
+ - Polygon Amoy Testnet
+ - Polygon zkEVM Cardona Testnet
+
 ## Quick Start
 
 These subgraphs only take a few minutes to set up. To get started, follow these three steps: