Update README

README.md

@@ -17,6 +17,16 @@ To learn more about deploying a Ponder instance, please consult their [docs](htt
 - Works on 30+ EVM chains
 - Conditional (only indexes the chains you're providing the RPC URL for)
 
+## Conditional indexing
+
+### Networks
+
+Ponder will only index the networks you've provided the RPC URL for. For example, if you only want to index the Ethereum network, you can set the `PONDER_RPC_URL_1` environment variable to the URL of your Ethereum node.
+
+### EntryPoint versions
+
+You can choose whether to index the EntryPoint 0.6.0, 0.7.0, or both by setting the `PONDER_ENTRYPOINT_VERSION` environment variable to `0.6`, `0.7`, or `all`. By default, Ponder will index EntryPoint v0.7.0.
+
 ## Roadmap
 
 - [ ] More networks