Add installation support matrix and recommended setup path

[alonshoa]

Problem

The installation page lists Docker runtime, devcontainer, and local Python paths, but it does not clearly rank them by supported user scenario or operating system expectations.

Scope

• Add a decision table for Docker runtime, VS Code devcontainer, and local Python install.
• Make the Docker runtime the recommended reproducible path for external users.
• Clarify Windows, macOS, Linux, and WSL expectations.
• Distinguish host commands from commands run inside the runtime/devcontainer.
• State local Python prerequisites explicitly: Manim, Manim Slides, FFmpeg, LaTeX/XeLaTeX, dvisvgm, and fonts.
• Add expected success output for studio doctor and studio doctor --catalog.

Acceptance Criteria

• A new user can choose the correct setup path without reading the whole site.
• Unsupported or partially supported combinations are stated explicitly.
• The documented recommended path matches the workflows exercised by CI/runtime smoke tests.
• mkdocs build --strict passes.

Dependencies

Use the current runtime and devcontainer implementation. Do not depend on a future installer or project builder.

Category

documentation, setup, onboarding