Update tips & tricks in docs (#2564)

Author: vkbo

docs/source/usage/howto.rst

@@ -43,6 +43,18 @@ Managing the Project
    project.
 
 
+Application Usage
+=================
+
+.. dropdown:: How can I increase the line height?
+   :animate: fade-in-slide-down
+
+   Unfortunately, in this case, novelWriter uses the plain text editor component of the underlying
+   framework (called Qt) which doesn't support changing the line height. However, you can choose an
+   editor font with larger leading (the spacing between the lines). A good font for this case is
+   `Noto <https://fonts.google.com/noto>`__, which comes in both Sans-Serif and Serif.
+
+
 Layout Tricks
 =============