Move mdast types to dev dependencies

Closes GH-41.

Reviewed-by: Titus Wormer <[email protected]>

Author: ChristianMurphy

package.json

@@ -31,7 +31,6 @@
   ],
   "types": "types/index.d.ts",
   "dependencies": {
-    "@types/mdast": "^3.0.0",
     "collapse-white-space": "^1.0.0",
     "detab": "^2.0.0",
     "mdast-util-definitions": "^3.0.0",
@@ -43,6 +42,7 @@
     "unist-util-visit": "^2.0.0"
   },
   "devDependencies": {
+    "@types/mdast": "^3.0.0",
     "browserify": "^16.0.0",
     "dtslint": "^3.0.0",
     "nyc": "^15.0.0",

readme.md

@@ -20,6 +20,12 @@
 npm install mdast-util-to-hast
 ```
 
+[npm][] with [TypeScript][] support:
+
+```sh
+npm install mdast-util-to-hast @types/mdast
+```
+
 ## Use
 
 Say we have the following `example.md`:
@@ -340,6 +346,8 @@ abide by its terms.
 
 [npm]: https://docs.npmjs.com/cli/install
 
+[typescript]: https://www.typescriptlang.org
+
 [license]: license
 
 [author]: https://wooorm.com