update course schedule for 2025 and adjust activity descriptions

[endersonmenezes]

This pull request updates the course schedule and content for the year 2025 in the docs/quero/estudar.md file. The changes include updating the semester dates, modifying the course schedule, and adding new content to the Python section.

Updates to the course schedule:

• Updated the semester dates to reflect the 2025 schedule.
• Changed the course introduction to include additional topics such as programming logic and tools.
• Updated the GitHub sessions to provide a more detailed introduction and distinguish between Git and GitHub.

Enhancements to the Python section:

• Added YAML to the list of file types covered in the Python file manipulation session.