Headings are simply swallowed in the text blocks

[ziegenberg]

When editing content and adding a textblock it states:

You can put your text content here. You can even use Markdown.

When adding the following content

# Heading 1

## Heading 2

Text

only the following gets rendered:

Text

This is very confusing for the user because the system just willy-nilly silently swallowed his text.