Add keyboard shortcuts that will increase/decrease the playback rate for video elements.
当前为
Updated version of the old video-element-rate-controller, with some added enhancements, such as syncing the playback speed with the Enhancer for YouTube extension, as well as being optimized to have a lower memory footprint.
By default, "[" will slowdown by 0.125x and "]" will speedup by 0.125x. This can be adjusted by changing the variable near the beginning of the script.
Tested working with Mozilla Firefox 62.0b12 (32-bit).
