feat: add docs location

Add docs location in the package.json, so CLI will now where to search for the help of the extension's commands.
Ignore the html folder, which CLI will generate at the root of the extension once it is installed.

.gitignore

@@ -53,4 +53,5 @@ nativescript-cloud-*.tgz
 **/.vs
 **/.vscode
 .DS_Store
-scratch/*
+scratch/*
+html/

.npmignore

@@ -13,3 +13,4 @@ tscommand-*.tmp.txt
 tsconfig.json
 tslint.json
 Gruntfile.js
+html/

package.json

@@ -101,6 +101,7 @@
       "run|cloud|android",
       "run|cloud|ios",
       "user"
-    ]
+    ],
+    "docs": "docs"
   }
 }