add noise cmd to doc

doc/README.md

@@ -138,14 +138,19 @@ Parameters:
  - `feedback`: Feedback, 0..1, default 0
  - `xfade_samp`: Crossfade samples (int), 0..5000, default 1250
 
+## `noise split index seed repeat_bytes`
+
+Inject random noise on the image.
+
+Parameters:
+ - `seed`, Random seed
+ - `repeat_bytes`, Amount of bytes to preload with random data and repeat
+    throughout the image slice
+
 ## TODO `echo split index delay`
 
 Run an echo filter on the given loaded file.
 
-## TODO `noise split index seed`
-
-Inject white noise on the image.
-
 ## `quicksave`
 
 Save the file on the same directory of the file specified by `load`, but