Ensure that opengraph images are available for each docs page

[leecalcote]

Current Behavior

See this example of a missing image - https://twitter.com/layer5/status/1782612959094624636

Desired Behavior

1. A general and generic branded Layer5 image - same as that used on layer5.io.
2. A specific image where appropriate (if at all) for specific docs pages.

Implementation

Reuse opengraph image from layer5.io site.

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Contributor Guide

• 🎨 Wireframes and designs for Layer5 site in Figma (open invite)

[iArchitSharma]

Fixed