Updated readme

[ric-v]

This pull request introduces a new "Video Guides" feature across the documentation and user interface, providing step-by-step visual guides for users. It also adds a carousel UI component with modal viewing for these guides, optimizes the navigation bar (especially for mobile), and updates the extension to version 0.6.0. Additionally, new commands related to Foreign Data Wrapper (FDW) management are registered in the extension manifest.

The most important changes are:

1. Video Guides Feature & UI Enhancements

• Added a new "Video Guides" section to README.md, MARKETPLACE.md, and as a carousel component in docs/index.html, showcasing setup and feature usage via animated GIFs. [1] [2] [3]
• Implemented a responsive, infinite-looping video carousel with indicators and expand-to-modal functionality, including supporting modal markup and accessibility improvements. [1] [2] [3] [4]

2. Navigation and Mobile Experience Improvements

• Optimized the navigation bar for mobile by hiding less important links, improving the install button, and hiding the hamburger menu via inline styles and CSS. [1] [2]
• Updated secondary call-to-action button to point to the new guides section and relabeled for clarity.

3. Extension Version and Command Additions

• Bumped the extension version from 0.5.3 to 0.6.0 in package.json.
• Registered new commands for managing Foreign Data Wrappers, Foreign Servers, and User Mappings in the extension manifest, enabling more advanced PostgreSQL features.

These changes collectively improve onboarding, feature discoverability, and advanced PostgreSQL management capabilities within the extension.