[Feature Request] Autostart #69

For that feature to work, the app needs to be constantly checking for the live feed.
We could only do so if a start image is present, but then we may have to watch for folder update (in case the user adds the image after starting the app). Another option is to have a "Reload" button like in #50 .

In @kadiwa4 's fork (#50), this was implemented as such:

• Add start image using the keyword start_auto_splitter that supports a custom comparison frequency (using <>)

Start image
The start image is similar to the reset image. You can reload the image using the "Reload" button.  
You can only have one start image with the keyword start_auto_splitter.  
The image must always have a custom threshold.  
You can also specify a custom comparison frequency using <>.  
The pause time is the amount of seconds AutoSplit will wait before checking for the start image once a run ends/is reset.