buffin/out description and examples

README.md

@@ -645,6 +645,8 @@ refer to the fundsp [readme](https://github.com/SamiPerttu/fundsp), and [docs](h
     - create a monitor node. sets the value of this circle's num to the latest sample that passed through this node. must have an order >= 1
 - `timer()`
     - when stacked with another node, this will maintain the current time of that node in this circle's number. must have an order >= 1
+- `buffin()` and `buffout()`
+    - these 2 are useful when you need to get samples from a point in the audio graph but not use them in audio (like when you want to use `render` to visualize audio). this is a channel with a buffer size (determined by the number of the buffin() circle. then this circle will have an audio node that passes audio through but sends it to the buffout(). connect them like this to link them: `buffin() 0 -> 1 bufout()` then whenever the audio node of buffout() processes (using apply or render) it will receive the samples sent from the audio graph. buffer can have a capacity of 1..100000. these nodes are basically like `monitor()`, but buffered instead of receiving only the latest sample. (see the `assets/scope` and `assets/circular-scope` scenes for examples)
 - `get()`
     - node: 1 in (index), 1 out (value)
     - copies this circle's array into node so it can be indexed at audio-rate. input is index, output is the value at that index