Some fixes and updates to run-colab guide:

- Add "Open in Colab" button.
- Update installation instructions for mxfp4 kernels after latest (and
  final) changes in transformers main.
- Fix reasoning_effort.
- Fix links to HF blog post.

Co-authored-by: vb <vaibhavs10@gmail.com>
Co-authored-by: lewtun <lewis.c.tunstall@gmail.com>
Co-authored-by: Alvaro Bartolome <36760800+alvarobartt@users.noreply.github.com>
Co-authored-by: sergiopaniego <sergiopaniegoblanco@gmail.com>

Author: 5 people