Add defaultHandlers export

Closes GH-58.

Reviewed-by: Titus Wormer <tituswormer@gmail.com>
Reviewed-by: Christian Murphy <christian.murphy.42@gmail.com>

index.js

@@ -7,4 +7,4 @@
  */
 
 export {one, all} from './lib/traverse.js'
-export {toHast} from './lib/index.js'
+export {defaultHandlers, toHast} from './lib/index.js'

lib/index.js

@@ -99,6 +99,8 @@ import {one} from './traverse.js'
 import {footer} from './footer.js'
 import {handlers} from './handlers/index.js'
 
+export {handlers as defaultHandlers}
+
 const own = {}.hasOwnProperty
 
 /**

readme.md

@@ -54,7 +54,7 @@ Which when running with `node example` yields:
 
 ## API
 
-This package exports the following identifiers: `toHast`, `all`, `one`
+This package exports the following identifiers: `toHast`, `defaultHandlers`, `all`, `one`
 There is no default export.
 
 ### `toHast(node[, options])`
@@ -244,6 +244,11 @@ Yields, in [hast][] (**note**: the `pre` and `language-js` class are normal
 }
 ```
 
+### `defaultHandlers`
+
+Object mapping mdast node types to functions that can handle them.
+See [`lib/handlers/index.js`](./lib/handlers/index.js)
+
 ### `all(h, parent)`
 
 Helper function for writing custom handlers passed to `options.handlers`.