[Docs] Add Visual Hook and Code Snippet to Landing Page

[Pabloo22]

The documentation landing page currently describes what the library does but doesn't show it. Users have to click through to "Examples" to see output or syntax.

Action Items:

• Add Hero Image: Insert a static image or GIF of a Job Shop Schedule (Gantt chart) directly after the main "JobShopLib" title and description in index.rst.
• Add Quick Start Block: Insert a code block immediately after the image that allows a user to copy-paste a working example.