[BUG] Non-supported HTML elements will be excluded without notice

[Builditluc]

General Information
Version: 0.6.0
Installation Method: cargo
Operating System: macOS
Backend (If changed during install): default

Describe the bug
When encountering a non-supported HTML element (e.g tables, mathematical equations, special elements like citations), they will simply get excluded and hidden from the user. This is the defined behavior, however, it leads to a few visual "bugs" when opening articles or just viewing sections only containing non-supported elements, as seen in the screenshots.

To Reproduce
Steps to reproduce the behavior:

1. Open the article List of content management systems or any other article containing non-supported HTML elements
2. The visual bug is visible

Expected behavior
Instead of just excluding the element from the article, there should be some text added instead that explains what element was hidden because it isn't supported.

Screenshots

This is an example of the visual bugs occurring because the user isn't informed that some elements are excluded, for reference, here is the Wikipedia article (it shows almost only tables, which are not supported)

Checklist

• checked other issues for the same bug
• read CONTRIBUTING.md

[Builditluc]

Blocking this issue because the following issues have to be completed first:

• Improve Changelog #135