Materials for the Python Skills tutorial

[Copilot]

Where to put new files:

• New files should go into a top-level subfolder, named after the article slug. For example: my-awesome-article

How to merge your changes:

1. Make sure the CI code style tests all pass (+ run the automatic code formatter if necessary).
2. Find an RP Team member on Slack and ask them to review & approve your PR.
3. Once the PR has one positive ("approved") review, GitHub lets you merge the PR.
4. 🎉

---

Adds materials for the How to Build the Python Skills That Get You Hired tutorial.

• python-skills/ directory with README and Excel skill roadmap resource
• README wording updated to "materials" for consistency with other tutorials in the repo

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.