Auto-Detect FFMPEG In PATH

[JumperBot]

Just a pretty quick suggestion checklist:

• [ ] Automatically detect if ffmpeg is already installed
• [ ] Use the PATH variable instead of copying the ffmpeg executables.
• [ ] If not installed yet, #5

This script pretty much has a big future to help lazy programmers like me to trim our coding session vids to only include important parts without copying a StackExchange answer for the hundredth time.