How to Create AppImage of Sigil 0.9.9. (or update existing AppImage)

How to Create AppImage of Sigil 0.9.9 (or update existing AppImage)

Well, I’m here to ask a little help (or, depending on your point of view, a huge) help.
I use Sigil under Linux (KDE Neon/Ubuntu 16.04lts) because it’s very simple to use to make notes and summaries for study.
I’ve read that the authors are not interested in a AppImage versions :frowning: .
Now thanks to your help, I have this working version: “Sigil-0.9.5-x86_64.AppImage”.
But I did not understand how to do an update version. Sorry for my ignorance.
Before writing here, I read and downloaded some scripts that do the same thing with LibreOffice and since they work very well, in fact I have created working versions of LibreOffice 6. I said to myself, perhaps by studying the code a little bit I can do the same thing with another program like Sigil.
But no. Nope.
I have difficulty understanding some parts of this script so I apologize, but I’m not a programmer. I try to learn. But in this case I put the white flag. I come in peace. Do not hit me right away (maybe later), but not now.
So. How I must do to achieve this goal?

Please ask the Sigil team to provide an official AppImage. I am happy to help them if needed.