Video player with Metadata track (type = selector)

Time-synced metadata is provided in a WebVTT file with kind="metadata". A data-meta-type attribute has value "selector", which is one of two types of supported metadata tracks (the other is "text"). With "selector" as the metadata type, the contents of the WebVTT file is used to identify blocks of existing hidden content that are shown at the designated times during playback. The keyword PAUSE on a single line within the WebVTT file causes the player to pause at the designated times.