Remove scene separator insertion after text

[vkbo]

Summary:

This PR changes the way scene separators are handled after encountering a text paragraph. Previously, any text would remove the blocker for inserting a scene separator. However, with the changes in #1711, only level 1 and 2 headers should block scene separator insertion. Text paragraphs should not affect it at all. Text inserted after a level 1 or 2 heading, followed by a leve 3 (scene) should flow uninterrupted.

Related Issue(s):

Related #1704

Reviewer's Checklist:

• The header of all files contain a reference to the repository license
• The overall test coverage is increased or remains the same as before
• All tests are passing
• All flake8 checks are passing and the style guide is followed
• Documentation (as docstrings) is complete and understandable
• Only files that have been actively changed are committed

[awqk]

The non-existence of a text paragraph before the scene header should be enough to block scene headers/headings.

In my use case (short story), I do not want either level 1 or level 2 headers, because pandoc and the docx template already take care of title, author etc. The document is built from "standard markdown" build output, prefixed with a yaml metadata block.

Admittedly, this is nothing serious, only a minor annoyance.

[vkbo]

Posting this here under a merged pull request will do nothing as I cannot keep track of suggestions in closed and completed threads. Feel free to post a feature request instead.