Clarify README.

README.md

 # jIO
 
-jIO is a promised-based JavaScript library that offers connectors to many storages (Dropbox, webdav, IndexedDB, GDrive, ...) using a single API. jIO supports offline use, replication, encryption and synchronization as well as querying of stored documents and attachments allowing to build complex client-side centric web applications.
+jIO is a promise-based JavaScript library that offers connectors to many storage backends (Dropbox, webdav, IndexedDB, GDrive, ...) using a single API. jIO supports offline use, replication, encryption and synchronization as well as querying of stored documents and attachments allowing to build complex client-side centric web applications.
 
 ### jIO Documentation
 
@@ -18,4 +18,5 @@ The documentation can be found on [https://jio.nexedi.com/](https://jio.nexedi.c
 RenderJS source code is hosted on Gitlab at [https://lab.nexedi.com/nexedi/jio](https://lab.nexedi.com/nexedi/jio) (Github [mirror](https://github.com/nexedi/jio/) - please use the issue tracker on Gitlab)
 
 ### jIO Test
-You can run tests after installing and building jIO by opening the */test/* folder
+
+You can run tests after installing and building jIO by opening the */test/* folder in a web browser.