add unit docs (#97)

docs/crocks/Unit.md

@@ -0,0 +1,73 @@
+# Unit
+
+`Unit a`
+
+--
+
+--
+
+```js
+--
+```
+
+`Unit` exposes the following functions on the constructor and instance:
+
+| Constructor | Instance |
+|:---|:---|
+| [`empty`](#empty), [`of`](#of), [`type`](#type) | [`ap`](#ap), [`chain`](#chain), [`concat`](#concat), [`empty`](#empty), [`equals`](#equals), [`inspect`](#inspect), [`map`](#map), [`of`](#of), [`type`](#type), [`value`](#value) |
+
+## Constructor
+
+### empty
+
+`Unit m => () -> m _`
+
+### of
+
+`Unit m => a -> m a`
+
+### type
+
+`() -> String`
+
+## Instance
+
+### ap
+
+`Unit m => m (a -> b) ~> m a -> m b`
+
+### chain
+
+`Unit m => m a ~> (a -> m b) -> m b`
+
+### concat
+
+`Unit m => m a ~> m a -> m a`
+
+### empty
+
+`Unit m => () -> m a`
+
+### equals
+
+`a -> Boolean`
+
+### inspect
+
+`() => String`
+
+### map
+
+`Unit m => m a ~> (a -> b) -> m b`
+
+### of
+
+`Unit m => a -> m a`
+
+### type
+
+`() -> String`
+
+### value
+
+`Unit m => m a ~> () -> undefined`