Docs: General Tutorial Suggestions

**Suggestions for all tutorials docs:**
- Add direct Github link at top of each tutorial for easy access to final working code (instead of bottom). Preferrably add direct Github icon for easy visiblity
- Use Miden client tools throughout entire tutorial series (currently only used from oracles tutorial onward).

Look at the tutorial markdown files in the repository. Identify where GitHub links are placed and update them to be at the top of each tutorial. Also, check which tutorials use Miden client tools and ensure they are referenced consistently from the start of the series. Verify changes by previewing the docs locally.

索引モデルが issue の本文から書いたものです。