[CI] Create PR deployment preview workflow

[marblom007]

Current Behavior

Contributors who open a PR don't receive a hyperlink to the built and temporarily deployed preview.

Desired Behavior

A hyperlink to a PR preview is extremely helpful for community members, who offer review on any of the PRs.

Implementation

See the other Hugo-based repositories (e.g. https://github.com/meshery-extensions/meshery-academy) for how to do this and copy/paste as much as possible (the whole thing, ideally).

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Contributor Guides and Handbook

• 🛠 Meshery Build & Release Strategy
• 📚 Instructions for contributing to documentation
• Meshery documentation site and source
• 🎨 Wireframes and designs for Meshery UI in Figma
• 🙋🏾🙋🏼 Questions: Discussion Forum and Community Slack
• 🧪 Meshery Test Plan Spreadsheet

[AbhishekMauryaGEEK]

Hi! I'd like to work on this issue

[AbhishekMauryaGEEK]

@marblom007 While investigating, I noticed kanvas-site already has build-and-preview-site.yml, and I also saw the ongoing CI cleanup in #237. I'll wait for clarification before preparing a PR so that the implementation aligns with the latest workflow changes.