hashtags at line beginning disappears when post is in markdown

Environment

• Installation type: Source
• Pleroma version: 2.2.2
• Elixir version: not known
• Operating system: Ubuntu
• PostgreSQL version: not known

Bug Description

When writing a post in Markdown, when a line starts with an hashtag, the hashtag is removed but appears in the hashtag page.

How-To

A line must starts with a # symbol + characters

#hastag
Maybe I’ll make the bug happen? 👀

The first line disappears, but the post appears in the hashtags #hashtag, Cf. screenshot below:

Cause

When a post is written in Markdown, headers are removed but Markdown's headers markup clash with hashtags markup, the two start with a hash # symbol.