AudioSample documentation is missing some methods (and has broken link) #719

Issue description

The documentation for the AudioSample class in the Sound library is missing the amp() and loop() methods from list of methods (even though these methods are used in the sample code shown). Also, the link to SoundFile in the Related section at the bottom of the page is broken (the link incorrectly points to https://processing.org/reference/libraries/sound/libraries/sound/SoundFile.html -- /libraries/sound is repeated in the URL).

URL(s) of affected page(s)

https://processing.org/reference/libraries/sound/AudioSample.html

Proposed fix

Add description of amp() and loop() methods in list of methods. Fix the broken link (should be https://processing.org/reference/libraries/sound/SoundFile.html)