Add docs to README

README.md

@@ -3,7 +3,7 @@
 ![Circle CI build
 status](https://circleci.com/gh/danwang/lambdanwang.svg?style=shield&circle-token=2299f0f86e45cf542f1855f46482c0e8dbe7b6f5)
 
-Lambdanwang is a small library for functional programming in JavaScript and
+Lambdanwang is a small library for functional programming with JavaScript and
 [Flow](https://flow.org/).
 
 
@@ -13,6 +13,15 @@ Lambdanwang is a small library for functional programming in JavaScript and
 yarn add lambdanwang --save
 ```
 
+## Docs
+### Containers
+- [Option](https://github.com/danwang/lambdanwang/blob/master/docs/option.md)
+- [Either](https://github.com/danwang/lambdanwang/blob/master/docs/either.md)
+
+### Functions
+- [compose](https://github.com/danwang/lambdanwang/blob/master/docs/functions.md#compose)
+- [mapObject](https://github.com/danwang/lambdanwang/blob/master/docs/functions.md#mapObject)
+
 ## License
 
 [MIT License](https://github.com/danwang/lambdanwang/blob/master/LICENSE)

docs/functions.md

@@ -0,0 +1,22 @@
+# Functions
+
+## `compose`
+
+Performs function composition.
+- `compose(f, g)` is equivalent to `(x) => f(g(x))`
+- `compose(f, g, h)` is equivalent to `(x) => f(g(h(x)))`
+
+## `mapObject`
+`<T, U>(Iterable<T>, (T) => [string, U]) => {[string]: U}`
+
+Given an Iterable and a mapper that returns a tuple, returns an object with the
+tuples as key-value pairs.
+
+**Example:**
+```jsx
+// Returns {_foo_: 3, _barbaz_: 6}
+λ.mapObject(
+  ['foo', 'barbaz'],
+  (s: string) => [`_${s}_`, s.length],
+);
+```