Documentation stuff!

New page for the effect list, updates to chanOsc, and links to instrument types from every "system" page.

doc/2-interface/README.md

@@ -13,6 +13,7 @@ primary topics:
 - [play/edit controls](play-edit-controls.md)
 - [instrument/wavetable/sample list](asset-list.md)
 - [song information](song-info.md)
+- [effect list](effect-list.md)
 - [pattern view](../3-pattern/README.md)
 - [instrument editor](../4-instrument/README.md)
 - [wavetable editor](../5-wave/README.md)

doc/2-interface/effect-list.md

@@ -0,0 +1,10 @@
+# effect list
+
+![effect list window](effect-list.png)
+
+this window provides a list of the effects that are available.
+
+for more details about these effects, see [the effects page](../3-pattern/effects.md).
+
+- **Chip at cursor**: the currently selected chip. the list only shows available effects for this chip.
+- menu button: opens a small list of effect categories. toggle each to change whether they're shown in the list.