This will document user interaction with the keyboard,
as currently we only have technical documentation. Things such as
gestures are documented here.

Change-Id: I6c7144b37d0dd087c8a28b36af2e4f2dfe0e06ba
Reviewed-by: Jarkko Koivikko <jarkko.koivikko@code-q.fi>
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>