README.md: Add a secion on Ivy

README.md

@@ -15,16 +15,28 @@ The package uses the `ivy` back end for the overview, see also
 
 There's also a ten minute [video demo](https://www.youtube.com/watch?v=VvnJQpTFVDc).
 
+## Ivy
+
+Ivy is a generic completion method for Emacs, similar to
+`icomplete-mode`. It aims to be more efficient, more simple, and more
+pleasant to use than the alternatives. It's also highly customizable
+and very small.
+
+To try it, just call <kbd>M-x</kbd> `ivy-mode`, and all generic
+completion, including file and buffer names, will be done with Ivy.
+
 ## Installation
 
 You can install the package from MELPA / GNU ELPA.
-Here is some minimal configuration:
+Here is some typical configuration:
 
 ```elisp
 (ivy-mode 1)
 (setq ivy-use-virtual-buffers t)
 (global-set-key "\C-s" 'swiper)
 (global-set-key "\C-r" 'swiper)
+(global-set-key (kbd "C-c C-r") 'ivy-resume)
+(global-set-key [f6] 'ivy-resume)
 ```
 
 ## Issues