Strong Suggestions

If you want an easy life installing and using the qownbackup system, here are some strong suggestions:

Be in your home directory when you untar your tar file.
Use all the defaults
Follow the instructions in the docs/INSTALL.md file.

Don't diverge from any of the preceding suggestions unless you have a good reason.

Downloads and Versions

The following are the official downloads for the qownbackup system:

Version 0.90 (Current)

Download the version you want into your home directory, and do NOTHING ELSE until you've read the following section...

Beginning Your Installation

If directory $HOME/qownbackup_installed already exists, move it so it doesn't get overwritten. That way, if you don't like something about the new version, you can restore the old one with a couple mv commands.
Download the .tgz for the version you want into your home directory.
Run the following command, assuming you want to install version 0.90: ` tar xzvf qownbackup_0.90.tgz`
Read the documentation in $HOME/qownbackup_installed/docs or $HOME/qownbackup_installed/docs/html
Follow the directions in the INSTALL.md or INSTALL.html file.

About the qownbackup system

The QOwnNotes software autosaves every ten seconds, which is nice but presents a problem. If you accidentally screw up your document the screwed up version gets autosaved, removing the good version. The Ctrl+z key combo (undo) can be used to undo what you screwed up, but sometimes things are so screwed up you'd rather abandon editing and start over with the last known good version. You can't do this with QOwnNotes unless you have it integrated with OwnCloud or NextCloud and also jump through some hoops.

What the qownbackup system gives you is autobackup to match QOwnNotes' autosave, complete with versioning. Assuming you leave the qb_interval_seconds at its default value 61, it checks for changes in every Markdown file every 61 seconds and backs up if changed. When you add the 61 to the ten second intervals QOwnNotes uses to autosave, this means your maximum data loss is 71 seconds, which isn't bad at all.

About QOwnNotes

QOwnNotes is a note taking and HTML/PDF authoring software that's extremely convenient to use. I keep it open and ready for use all the time. In the future I plan to use it as the front end to a book authoring software stack.

QOwnNotes is very unusual software in many ways. Two of those ways can be inconvenient:

QOwnNotes' autosave can, under certain circumstances, overwrite a good file with bad stuff, with no way to rescue the good text.
Organization of your notes in QOwnNotes can be difficult.

The qownbackup system completely takes care of inconvenience #1. As far as #2, when I know QOwnNotes better I'll either report on how to split your notes into categories, or create software to make it possible.