I use a single text file, have done this for decades. I dump everything into it and don't worry too much about structure, it's an incredible resource for "remembering" minutia, things like "what was that server that i thought might have had some issues last August?" Just a quick control-S and I'm there. My current 7+ year old notes file has about 100K lines in it right now. I can tell you what I was doing last year,…
I also added a vim command to push it to github while editing. These just remove barriers to opening and syncing the file, but the concept is the same.
You can see the result here: https://github.com/jodavaho/bashlog