Update guide.md

docs/guide.md

@@ -11,7 +11,22 @@ version 0.1
 * Input format (https://sites.google.com/site/germeval2014ner/data)
 * Data preparation ([Python tools](https://github.com/cneud/ner.edith/tree/master/tools))
 * Overview of Editor Features
+  * Navigation
+    * use mouse wheel to scroll up and down
+    * use navigation `<<` and `>>` to move faster
 * Data export/Saving progress
+
+  The editor runs fully locally in the browser. Therefore it can not automatically save any changes you made to disk. You have to use the "Save changes" button in order to do that manually from time to time.
+
+  If your browser automatically saves all downloads to your "Downloads" folder, you might want to configure it such that it asks you where to save it.
+
+  Configuration option in Firefox:
+
+![Screenshot](./../.screenshots/firefox.png)
+
+Configuration option in Chrome:
+
+![Screenshot](./../.screenshots/chrome.png)
 * FAQ
 * Troubleshooting