feat: add parallel parsing example and enhance MRT support

- Introduced a new example (`parse_single_file_parallel.rs`) for parallelized parsing of RIB dump files using `crossbeam-channel`.
- Added `set_peer_table` method to `Elementor` for peer index table configuration.
- Updated dependencies to include `crossbeam-channel`.

Author: digizeph

Cargo.toml

@@ -123,6 +123,7 @@ tempfile = "3"
 ctrlc = "3.4"
 tracing = "0.1"
 tracing-subscriber = "0.3"
+crossbeam-channel = "0.5"
 
 # This list only includes examples which require additional features to run. These are more in the examples directory.
 [[example]]