[SW-775] Fix link to updated location of development documentation (#631)
[SW-775] Fix link to updated location of development documentation (#631)

* [SW-775] Fix link to updated location of development documentation

* Point users to online help rather than files in github repo

* for master only, add "available here" parenthetical

h2oai/sparkling-water,h2oai/sparkling-water,h2oai/sparkling-water,h2oai/sparkling-water