Fixes #9, by killing the ffmpeg process if it does not exit within 1 second

[JPasterkampRotec]

• Added a editorconfig because this project was written with spaces instead of tabs, so spaces should be enforced in everyone's editor.
• Passing cancellation token into Stream.ReadAsync.
• Killing the ffmpeg process if it will not cancel within 1 second.

[JPasterkampRotec]

I tried linking this pull request to this issue but don't know how

[tinohager]

• https://github.com/nager/Nager.VideoStream/issues/9