Provide install instructions in README

Hmmm looking again at this module's README file, I can see that more documentation would indeed be useful.

Smart Date isn't declared as a dependency because the Date Augmenter API is meant to be compatible with other formatters, if they implement a small amount of code. That said, Smart Date is currently the only compatible formatter I know of.

As such, a more explicit set of setup instructions would be:

• Configure your date field to use a display formatter compatible with the Date Augmenter API, such as one of the Smart Date formatters
• In the formatter's display configuration, enable this module's Augmenter. Note that for recurring events, you can choose to add calendar links to individual dates (which will only add a single date), to the series text (which will add the entire series to the calendar), or both.

That would work perfectly!

I added the text from #4, and some information about the configuration options.

I've reviewed the changes in merge request !13, and the detailed installation and configuration instructions have been added to the README file as discussed. These additions should help users set up the module correctly and address the initial confusion.
RTBC +
Thankyou.

Thanks for the feedback! Merged in.