thumnail size lint

Author: teh-cmc

examples/python/stdio/README.md

@@ -4,6 +4,7 @@ python: https://github.com/rerun-io/rerun/tree/latest/examples/python/stdio/main
 rust: https://github.com/rerun-io/rerun/tree/latest/examples/rust/stdio/src/main.rs?speculative-link
 cpp: https://github.com/rerun-io/rerun/tree/latest/examples/cpp/stdio/main.cpp?speculative-link
 thumbnail: https://static.rerun.io/stdio/25c5aba992d4c8b3861386d8d9539a4823dca117/480w.png
+thumbnail_dimensions: [480, 298]
 ---
 
 <picture>