ARROW-3309: [JS] Missing links from DEVELOP.md

Rendered output: [DEVELOP.md](https://github.com/kszucs/arrow/blob/15572083678aebbe8a931195aa4d1fa9c7cc0b78/js/DEVELOP.md)

Author: Krisztián Szűcs <[email protected]>

Closes apache#2618 from kszucs/ARROW-3309 and squashes the following commits:

1557208 <Krisztián Szűcs>  add missing links in DEVELOP.md

Author: kszucs

js/DEVELOP.md

@@ -99,3 +99,8 @@ Once generated, the flatbuffers format code needs to be adjusted for our build s
     ```
 1. Add `/* tslint:disable:class-name */` to the top of `Schema.ts`
 1. Execute `npm run lint` to fix all the linting errors
+
+[1]: mailto:[email protected]
+[2]: https://github.com/apache/arrow/tree/master/format
+[3]: https://issues.apache.org/jira/browse/ARROW
+[4]: https://github.com/apache/arrow