Checklist

• This is a bug report.
• This is a feature request.
• This is a plugin (improvement) request.
• I have read the contribution guidelines.

Description

Some documentation still contains livestreamer version numbers, including the API reference. (things implemented in 1.6.0 when streamlink isn't even to 1.0.0)

Suggested solution

Instead of removing these version numbers, we should prefix them so as to say that they are livestreamer versions. (i.e; "1.6.0"->"ls1.6.0" or "livestreamer 1.6.0")