docs: clarify pool-indexer module comment

Author: AryanGodara

crates/liquidity-sources/src/uniswap_v3/pool_indexer.rs

@@ -1,6 +1,6 @@
 //! HTTP client for the Uniswap V3 pool-indexer service. Implements
-//! [`V3PoolDataSource`] so the driver can swap this in place of the
-//! subgraph client without touching anything else.
+//! [`V3PoolDataSource`] so the driver can swap this in place of the subgraph
+//! client without touching anything else.
 //!
 //! The pool-indexer always returns at-head data — it doesn't support
 //! historical queries. `block_number` arguments are ignored; the block