Make a few minor updates in the README

This removes a reference to the obsolete variable
ido-cr+-no-default-action and fixes a typo.

README.md

@@ -18,17 +18,17 @@ major update. The previously separate ido-ubiquitous package has been
 merged into ido-completing-read+, which now provides all the features
 of both packages. The distinction between "new" and "old" default
 selection styles has been eliminated and replaced by a new variable
-`ido-cr+-no-default-action` (see [FAQ][1] for details), and the
-override system has been accordingly simplified into just a blacklist
-and a whitelist. If you have previously customized any ido-ubiquitous
-options, be sure to check out
+`ido-cr+-nil-def-alternate-behavior-list` (see [FAQ][1] for details),
+and the override system has been accordingly simplified into just a
+blacklist and a whitelist. If you have previously customized any
+ido-ubiquitous options, be sure to check out
 
     `M-x customize-group ido-completing-read+`
     
 after updating to 4.0 and make sure the new settings are to your
 liking.
 
-This short-lived ido-describe-fns package has likewise been subsumed
+The short-lived ido-describe-fns package has likewise been subsumed
 into this one.
 
 [1]: #why-does-ret-sometimes-not-select-the-first-completion-on-the-list--why-is-there-an-empty-entry-at-the-beginning-of-the-completion-list--what-happened-to-old-style-default-selection