Documentation: Update details of The Linux Kernel Module Programming Guide

Recently, the content and examples of the book "The Linux Kernel Module
Programming Guide" are being actively maintained and added on Github[1].
Currently, the book is being regularly built into webpage and pdf
file using Github static page[2].

[1]: https://github.com/sysprog21/lkmpg
[2]: https://sysprog21.github.io/lkmpg/Signed-off-by: Chun-Hung Tseng <henrybear327@gmail.com>
Link: https://lore.kernel.org/r/20210820222152.971174-1-henrybear327@gmail.com
[jc: fixed docs-build warnings]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/process/kernel-docs.rst

@@ -126,15 +126,17 @@ On-line docs
         describes how to write user-mode utilities for communicating with
         Card Services.
 
-    * Title: **Linux Kernel Module Programming Guide**
+    * Title: **The Linux Kernel Module Programming Guide**
 
-      :Author: Ori Pomerantz.
-      :URL: https://tldp.org/LDP/lkmpg/2.6/html/index.html
-      :Date: 2001
+      :Author: Peter Jay Salzman, Michael Burian, Ori Pomerantz, Bob Mottram,
+        Jim Huang.
+      :URL: https://sysprog21.github.io/lkmpg/
+      :Date: 2021
       :Keywords: modules, GPL book, /proc, ioctls, system calls,
         interrupt handlers .
-      :Description: Very nice 92 pages GPL book on the topic of modules
-        programming. Lots of examples.
+      :Description: A very nice GPL book on the topic of modules
+        programming. Lots of examples. Currently the new version is being
+        actively maintained at https://github.com/sysprog21/lkmpg.
 
     * Title: **Global spinlock list and usage**