Delete communicating and move the missing info into js-plugin-api

Summary: Documents init in the API reference and deletes the now redundant communicating page.

Reviewed By: danielbuechele

Differential Revision: D15198128

fbshipit-source-id: a9b88632b74edd7d9656ed888192db1fbe7f3642

website/i18n/en.json

@@ -12,10 +12,6 @@
       "extending/arch": {
         "title": "Architecture"
       },
-      "extending/communicating": {
-        "title": "Device Communication",
-        "sidebar_label": "Device Communication"
-      },
       "extending/create-plugin": {
         "title": "Mobile Setup"
       },

website/sidebars.json

@@ -34,7 +34,6 @@
       "extending/js-setup",
       "extending/js-plugin-api",
       "extending/create-table-plugin",
-      "extending/communicating",
       "extending/ui-components",
       "extending/styling-components",
       "extending/create-plugin",