Update node/README.md

Co-authored-by: Ben Holden-Crowther <4144334+blrhc@users.noreply.github.com>

node/README.md

@@ -31,7 +31,7 @@ cargo build --release
 
 This produces the binary in `./target/release/joystream-node`
 
-### Running Local development chain
+### Running local development chain
 
 ```bash
 cargo run --release -- --dev