add many experimental plugins

doc/README.md

@@ -181,9 +181,67 @@ just be different.
 
 ## `gate split index switch threshold attack hold decay gaterange` 
 
+**TODO:** find good parameters
+
  - switch (bool): 0..1, default 0
  - threshold (dB): -70..12, default -70
  - attack (ms): 0.1..500, default 30
  - hold (ms): 5..3000, default 500
  - decay (ms): 5..4000, default 1000
  - gaterange (dB): -90..-20, default -90
+
+## `detune split index detune mix output latency`
+
+> A low-quality stereo pitch shifter for the sort of chorus and detune effects found on multi-effects hardware.
+
+ - detune (cents, left channel is lowered in pitch, right channel is raised): 0..1, default 0.2
+ - mix (wet/dry mix): 0..1, default 0.9
+ - output (level trim): 0..1, default 0.5
+ - latency (trade-off between latency and low-freq response): 0..1, default 0.5
+
+other presets:
+ - stereo detune: 0.2 0.9 0.5 0.5
+ - out of tune: 0.8 0.7 0.5 0.5
+
+
+## `overdrive split index drive muffle output`
+
+> Possible uses include adding body to drum loops, fuzz guitar, and that 'standing outside a nightclub' sound. This plug does not simulate valve distortion, and any attempt to process organ sounds through it will be extremely unrewarding!
+
+ - drive (amount of distortion): 0..1, default 0
+ - muffle (gentle low-pass filter): 0..1, default 0
+ - output (level trim): 0..1, default 0.5
+
+## `degrade split index headroom quant rate post_filt non_lin output`
+
+> Sample quality reduction
+
+**NOTE:** finding the right parameters is HARD for this plugin.
+
+ - headroom (peak clipping threshold): 0..1, default 0.8
+ - quant (bit depth, typically 8 or below for "telephone" quality): 0..1, default 0.5
+ - rate (sample rate): 0..1, default 0.65
+ - post_filt (low-pass filter to muffle the distortion): 0..1, default 0.9
+ - non_lin (additional harmonic distortion "thickening"): 0..1, default 0.58
+ - output: 0..1, default 0.5
+
+## `repsycho split index tune fine decay thresh hold mix quality`
+
+**NOTE:** HARD to find good parameters
+
+ - tune (coarse tune, semitones): 0..1, default 1
+ - fine (fine tune, cents): 0..1, default 1
+ - decay (adjust envelope of each trunk, a fast decay can be useful while setting up): 0..1, default 0.5
+ - thresh (trigger level to divide the input into chunks): 0..1, default 0.6
+ - hold (minimum chunk length): 0..1, default 0.45
+ - mix (mix original signal with output): 0..1, default 1
+ - quality (quality, bool. the high=1 setting uses smoother pitch-shifting and allows stereo): 0..1, default 0
+
+## `talkbox split index wet dry carrier quality`
+
+> High resolution vocoder
+
+ - wet: 0..1, default 0.5
+ - dry: 0..1, default 0
+ - carrier: 0..1, default 0
+ - quality: 0..1, default 1