MiniApp-PWA Comparison table updated

[espinr]

This PR is a review of the existing table, as I volunteered in #177 . Main changes:

• Status of W3C specifications updated.
• Some new MiniApp APIs included in the table
• Improved readability of the table with Yes/No/Partial values, including the details in a
  structure inside the cells. Using homogeneous terms.
• Other minor editorial changes and enhancement of the code (adding abbrs, hreflangs, etc.)

[xfq]

Preview: https://htmlpreview.github.io/?https://raw.githubusercontent.com/espinr/miniapp/comparison-update/white-paper/comparison.html