Is there any Linux software where I could edit rendered Markdown (preview)?
I know that I could edit the text file directly. But I was wondering if some software let me edit the rendered HTML and text file could get updated?
It sounds like what you really want is a "WYSAWYG" (What You See Approximates What You Get) editor for MarkDown. If that's actually the case, I can point you to Typora; I use the Windows version, and it works nicely.
I don't recommend Typora, as it is closed source. I found:
Somewhat along the lines of Typora is Abricotine, which also has just the one pane which serves as both the live previewer and the editor. You do not "switch modes" or have side-by-side panes. It does visually expose more raw Markdown than Typora. Most notably, the basic formatting characters (
* for italics and bold,
~ for strike-through, and
# for headings) remain visible at all times, even though the text is rendered in the desired style.
I guess this behavior could be considered a positive or a negative. I personally find that Abricotine's rendering looks a bit chaotic and incohesive, since most of the basic formatting has exposed Markdown but the more complex formatting (like to-do lists) is displayed in a much more sophisticated-looking, graphical, and immersive way (kind of like how Typora handles everything).
So, it doesn't seem as polished as Typora, but it is open source. The download page has prebuilt versions for Linux, Mac, and Windows, as well as source-only.
For those looking for multiplatform options, it may be worth checking out this related question which asks for the same essential feature except running on Windows instead of Linux. (That is actually where I first learned of Abricotine.)