Well, first I’d like to say that I’m not quite sure if a single page can be called a tutorial for a program as complex as Shotcut. That said, even if it is a little short, it could be helpful for someone who have never used a video editor before.
However, if you intend to aim this tutorial at an English speaking audience, I would suggest that you check your texts before publishing. My first language is not English (obviously) and even I could find many errors. And a few wrong informations that could be confusing to new users.
For example, you say : “You can fade audio in Shotcut very easily. You need to click the top corner of your audio track and drag horizontally to drag-out a fade rectangle.”
In my opinion, it would be more accurate to mention that positioning the mouse cursor at one of the top corners of the audio tracks makes a circle appear and dragging this circle horizontally will adjust the fade length. Visually represented by a fade triangle (not rectangle).
Another example : “After editing your video you can export it to the media file”. You probably meant “After editing your project you can export it as a media file”.
You also say : “You can see the master tab in the corner of the timeline. you can mute the sound of audio files and hide your video file and pictures. After you can always use the lock track feature.”
But the mute, hide and lock buttons are not in the Master tab, they are at the left end of each track (not sure what that area is called in fact… Track header box maybe ?). And why not mention that you could do the same on a video track for video fade-in and fade-out ?
I salute and respect your will and effort to try to help the Shotcut community, but I think your page need a little more work to be really helpful.