Updated Help page; can add your company to listing

See #2306

docs/community/help.rst

@@ -7,3 +7,11 @@ For professional DKAN development services and support:
 - `Angry Cactus <http://www.angrycactus.biz/>`_
 - `National Democratic Institute <https://www.nditech.org/project/dkan>`_
 - `Annai <http://landing.dkan.annai.co.jp/>`_
+
+Add your company
+=================
+
+If you provide DKAN development and/or support services, here's how to add your company to business directory:
+
+- Create a /dkan page on your website (ex: https://civicactions.com/dkan/)
+- Create a [new issue](https://github.com/GetDKAN/dkan/issues/new) and include logo, company name, link to /dkan page, brief description of services with respect to DKAN