example: add simpling example and test (modelcontextprotocol#289)

Signed-off-by: jokemanfire <[email protected]>

Author: jokemanfire

examples/clients/Cargo.toml

@@ -55,4 +55,4 @@ path = "src/auth/oauth_client.rs"
 
 [[example]]
 name = "clients_sampling_stdio"
-path = "src/sampling_stdio.rs"
+path = "src/sampling_stdio.rs"