Customize TipTap, esp. table

[MacLake]

As we use Fomantic UI, we nee some adoptions before we can consider switching to TipTap:

The first and most important thing that I noticed is that we need to add attributes to HTML table tags,:

<table class="ui table">
</table>

Only then the nice stackable table design is being applied, see also Fomantic UI tables. A start would be to just add the attributes "ui table" to every <table>element, but some more customisations would be nice, so that you can choose other variants of <table>, <tr> and <td>. Most other elements can be implemented as CMS plugins, but probably also customisations of other tags like <h1…6>, <ul>, <ol> etc. would make sense.