Docs: Improve grids options docs, document initial nodes (#1727)
Docs: Improve grids options docs, document initial nodes (#1727)

* docs grids: document grid options, initial nodes

* edit, fix links

* remove references to #1323

kontena/kontena,mikkopiu/kontena,mikkopiu/kontena,kontena/kontena,kontena/kontena,mikkopiu/kontena,mikkopiu/kontena,kontena/kontena