Update intro.md

Author: hohse

docs/intro.md

@@ -56,13 +56,18 @@ Great work on creating your first project! But that project is still empty. To c
 
 > :exclamation: **Please note** At the moment, OpenQDA only supports *.RTF and *.TXT files. Other common file formats, like *.DOC, *.DOCX or *.PDF files might be supported at a later date. OpenQDA has a plug-in architecture: We, you, or other people in the community are able create import plug-ins for other file formats.
 
-Now, to upload an existing file, click the **Import** button to select a *.TXT or *.RTF file. Click on the title of the document to see the contents of the file in the editor in the right pane. Now you can edit the document.
+Now, to upload an existing file, click the **Import** button to select a *.TXT or *.RTF file. Click on the title of the document to see the contents of the file in the editor in the right pane. Now you can edit the document and prepare it for coding, if necessary.
 
+![Importing a document file into OpenQDA](../static/img/document_selection_96dpi.png "Importing a document file")
 
+The editor works just like any word processor you know. Here you can add or delete text and also format the text according to your needs. Don't forget to click the **Save** button above the text to make your changes permanent. This way you can even create documents directly in OpenQDA. Just click the **New File** butten next to the **Import** button on the top left. You can then type or paste your text contents (for example from a *.PDF file) into the newly created document. Again, don't forget to save your work.
+If you click on the three little dots next to a file name, you can also rename the document or delete it from your project.
 
-You can also create new text documents when you click **New file**. You can then paste your text contents into the new document.
+When you are done editing your file, you can press the **Lock and Code** button to lock the file and start coding.
 
-When you are ready with editing, you can press the **Lock and Code** button to lock the file and start coding.
+> :exclamation: **Please note** Please be aware that once you started coding a document, you can not unlock it anymore to make further edits. Once coding started, editing ends.
+
+![Editing a document file in OpenQDA](../static/img/document_preparation_96dpi.png "Editing a document file")
 
 ## Coding the text