Update docs to show comma-separated --uri syntax

Author: rockbmb

README.md

@@ -184,21 +184,29 @@ cargo build --features try-runtime --release && cp target/release/substrate .
 
 ```bash
 # Assuming local nodes are running (e.g., `./substrate --dev --tmp --ws-port 9999`).
-# Multiple --uri flags can be provided for parallel state download.
+# Multiple URIs can be provided for parallel state download, either
+# comma-separated or via repeated --uri flags.
 try-runtime \
     --runtime /path-to-substrate/target/release/wbuild/my-runtime.wasm \
     on-runtime-upgrade \
     --disable-mbm-checks \
     live \
-    --uri ws://localhost:9999 \
-    --uri ws://localhost:9998
+    --uri ws://localhost:9999,ws://localhost:9998
     ...
 ```
 
 To speed up state download, you can provide multiple URIs for parallel fetching:
 
 ```bash
 # assuming multiple substrate nodes running on ports 9999, 9998, 9997
+# comma-separated:
+try-runtime \
+    --runtime /path-to-substrate/target/release/wbuild/my-runtime.wasm \
+    on-runtime-upgrade \
+    live \
+    --uri ws://localhost:9999,ws://localhost:9998,ws://localhost:9997
+
+# or repeated flags:
 try-runtime \
     --runtime /path-to-substrate/target/release/wbuild/my-runtime.wasm \
     on-runtime-upgrade \
@@ -210,8 +218,8 @@ try-runtime \
 
 * Same as the previous example, but run it at specific block number's state and using the live
   polkadot network. This means that this block hash's state should not yet have been pruned by
-  the node running at `rpc.polkadot.io`. Multiple `--uri` flags can be provided for parallel
-  state download.
+  the node running at `rpc.polkadot.io`. Multiple URIs can be provided for parallel
+  state download (comma-separated or via repeated `--uri` flags).
 
 ```bash
 try-runtime \
@@ -236,8 +244,7 @@ For faster snapshot creation with large state, use multiple RPC endpoints:
 
 ```bash
 try-runtime --runtime existing create-snapshot \
-    --uri ws://localhost:9999 \
-    --uri ws://localhost:9998 \
+    --uri ws://localhost:9999,ws://localhost:9998 \
     -- my-snapshot.snap
 ```
 

cli/main.rs

@@ -200,21 +200,28 @@
 //!
 //! ```bash
 //! # Assuming local nodes are running (e.g., `./substrate --dev --tmp --ws-port 9999`).
-//! # Multiple --uri flags can be provided for parallel state download.
+//! # Multiple URIs can be provided for parallel state download, either
+//! # comma-separated or via repeated --uri flags.
 //! try-runtime \
 //!     --runtime /path-to-substrate/target/release/wbuild/my-runtime.wasm \
 //!     on-runtime-upgrade \
 //!     --disable-mbm-checks \
 //!     live \
-//!     --uri ws://localhost:9999 \
-//!     --uri ws://localhost:9998
+//!     --uri ws://localhost:9999,ws://localhost:9998
 //!     ...
 //! ```
 //!
 //! To speed up state download, you can provide multiple URIs for parallel fetching:
 //!
 //! ```bash
-//! # assuming multiple substrate nodes running on ports 9999, 9998, 9997
+//! # comma-separated:
+//! try-runtime \
+//!     --runtime /path-to-substrate/target/release/wbuild/my-runtime.wasm \
+//!     on-runtime-upgrade \
+//!     live \
+//!     --uri ws://localhost:9999,ws://localhost:9998,ws://localhost:9997
+//!
+//! # or repeated flags:
 //! try-runtime \
 //!     --runtime /path-to-substrate/target/release/wbuild/my-runtime.wasm \
 //!     on-runtime-upgrade \
@@ -226,8 +233,8 @@
 //!
 //! * Same as the previous example, but run it at specific block number's state and using the live
 //!   polkadot network. This means that this block hash's state should not yet have been pruned by
-//!   the node running at `rpc.polkadot.io`. Multiple `--uri` flags can be provided for parallel
-//!   state download.
+//!   the node running at `rpc.polkadot.io`. Multiple URIs can be provided for parallel state
+//!   download (comma-separated or via repeated `--uri` flags).
 //!
 //! ```bash
 //! try-runtime \
@@ -252,8 +259,7 @@
 //!
 //! ```bash
 //! try-runtime --runtime existing create-snapshot \
-//!     --uri ws://localhost:9999 \
-//!     --uri ws://localhost:9998 \
+//!     --uri ws://localhost:9999,ws://localhost:9998 \
 //!     -- my-snapshot.snap
 //! ```
 //!