update documentation

NEWS.org

@@ -46,7 +46,7 @@
    - the ~verify~ command for checking signatures has been updated, and is more
      informative
 
-   - new commands ~fields~ and ~flags~ give information about the message fields and
+   - a new command ~mu fields~ provides information about the message fields and
      flags for use in queries. The information is the same information that ~mu~
      uses and so stays up to date.
 
@@ -88,12 +88,16 @@
 
     - A new ~defcustom~, ~mu4e-view-open-program~ for starting the appropriate
       program for a give file (e.g., ~xdg-open~). There are some reasonable
-      defaults for various systems.
+      defaults for various systems. This can also be set to a function.
 
     - For performance testing, you can set the variable
       ~mu4e-headers-report-render-time~ to ~t~ and ~mu4e~ will report the
       search/rendering speed of each query operation.
 
+    - As an additional measure to limit the number of contacts that mu4e loads
+      for auto-completions, there's ~mu4e-compose-complete-max~, which by default
+      is set to *2000*, so you can auto-complete your 2000 closest friends.
+
     - Removed ~make-mu4e-bookmark~ which was obsoleted in version 1.3.9.
 
     - undo is now supported across message-saves
@@ -123,8 +127,8 @@
       - =mu4e-proc.el= has been renamed =mu4e-server.el=.
 
       - Between =mu= and =mu4e=, contact cells are now represented as a plist ~(:name
-        "Foo Bar" :email "foobar@example.com")~ rather than a cons-cell ~("Foo
-        Bar" . "foobar@example.com").~
+	"Foo Bar" :email "foobar@example.com")~ rather than a cons-cell ~("Foo
+	Bar" . "foobar@example.com").~
 
 
     - Because of all these changes, it is recommended you remove older version