docs: cache sharing WithPeerBlockRequestFilter

docs/environment-variables.md

@@ -160,7 +160,9 @@ Automated version of `RAINBOW_PEERING` which does not require providing multiadd
 Instead, it will set up peering with peers that share the same seed (requires `RAINBOW_SEED_INDEX` to be set up).
 
 > [!NOTE]
-> Runs a separate light DHT for peer routing with the main host if DHT routing is disabled.
+> Runs:
+> - a separate light DHT for peer routing with the main host if DHT routing is disabled.
+> - a bitswap server with despite `WithPeerBlockRequestFilter` may increase resource usage, as every requested CID will be also broadcasted to peered nodes
 
 Default: `false` (disabled)