In the DynamicsCompressor example, add a way to modify the other compressor parameters

[sole]

Compressor nodes have a number of attributes we're not accessing: https://webaudio.github.io/web-audio-api/#the-dynamicscompressornode-interface

• threshold
• knee
• ratio
• attack
• release

These are AudioParams so they can be automated etc (see the reference for the allowed value ranges per attribute).

It would be great to have sliders (<input type="range">) that let us change these values to see how the compression node reacts and how it sounds differently.

For these purposes we could change them immediately without using AudioParam automations, e.g. add a listener to the change event on the threshold slider and then do something like

var value = thresholdSlider.value;
var now = audioContext.currentTime;
compressor.threshold.setValueAtTime(value, now);

The DynamicsCompressor example is at: https://github.com/mozdevs/WebAudio-examples/tree/gh-pages/DynamicsCompressor