Select the ‘Window’ tab and then click “Application options”, this will open the screen as shown above. Click on ‘keys’ and then simply enter ‘doc’ (without the quotes) into the search bar (see example above). This will show the export option you need.
Click on it, then click on ‘binding’ entry field at the bottom, then click the keyboard combination which you want to use. Be sure that you don’t get any warnings about conflicts. I discovered that control-alt-e should be usable here.
Then click apply, click ok and you’ll probably be asked to restart the program. Afterwards you should be able to start your export using this keyboard combination.
The second option which I can think of is a plugin. However I need to get back to you on that one because although I do know which class I’d need to use (DocumentationManager) I’ll need to check a few things for myself first.