Make it easier to enable Abbrev mode by default

* lisp/cus-start.el: Make 'abbrev-mode' customizable.
* doc/emacs/abbrevs.texi (Abbrev Concepts):
* etc/NEWS:
* src/buffer.c (syms_of_buffer): <abbrev-mode>: Document
enabling Abbrev mode by default in all buffers by customizing
'abbrev-mode' to a non-nil value.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/buffer.c b/src/buffer.c
index e44b6daf587..3ef95626600 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -5218,8 +5218,10 @@ Format with `format-mode-line' to produce a string value.  */);
                      doc: /* Local (mode-specific) abbrev table of current buffer.  */);
 
   DEFVAR_PER_BUFFER ("abbrev-mode", &BVAR (current_buffer, abbrev_mode), Qnil,
-                     doc: /*  Non-nil if Abbrev mode is enabled.
-Use the command `abbrev-mode' to change this variable.  */);
+                     doc: /* Non-nil if Abbrev mode is enabled.
+Use the command `abbrev-mode' to change the value of this variable in
+the current buffer.  Customize this variable to non-nil to enable Abbrev
+mode by default in all buffers.  */);
 
   DEFVAR_PER_BUFFER ("fill-column", &BVAR (current_buffer, fill_column),
                      Qintegerp,