📝 Add a proper README file with section and links

Fix #1

docs/configuration/transport/dropbox.md

@@ -0,0 +1,21 @@
+# Dropbox transport configuration
+
+ ## JSON
+```
+"Dropbox": {
+  "token": "your-token-here",
+},
+```
+ ## General 
+
+To generate your access token, you need to go to your [`App Console`](https://www.dropbox.com/developers/apps).
+
+Then,
+ 1. Create a new app
+ 2. Select DropboxAPI, "App folder" and give it a unique name.
+ 3. Click on the button next to "Generate access token"
+ 
+ ## Options
+token (mandatory)   = access token
+
+