docs: add dependabot badge to README

Author: jrolfs

README.md

@@ -8,6 +8,7 @@
 
 [![Build Status][build-badge]][build]
 [![Code Coverage][coverage-badge]][coverage]
+[![Dependabot Status][dependabot-badge]][dependabot]
 [![version][version-badge]][package] [![MIT License][license-badge]][license]
 
 ## The problem
@@ -110,6 +111,9 @@ MIT
 [coverage-badge]:
   https://img.shields.io/codecov/c/github/hoverinc/hover-javascript.svg
 [coverage]: https://codecov.io/github/hoverinc/hover-javascript
+[dependabot-badge]:
+  https://api.dependabot.com/badges/status?host=github&repo=hoverinc/hover-javascript
+[dependabot]: https://dependabot.com
 [version-badge]: https://img.shields.io/npm/v/@hover/javascript.svg
 [package]: https://www.npmjs.com/package/@hover/javascript
 [license-badge]: https://img.shields.io/npm/l/@hover/javascript.svg