docs: get rid of kernel-doc-nano-HOWTO.txt

Everything there is already described at
Documentation/doc-guide/kernel-doc.rst. So, there's no reason why
to keep it anymore.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/00-INDEX

@@ -228,8 +228,6 @@ isdn/
 	- directory with info on the Linux ISDN support, and supported cards.
 kbuild/
 	- directory with info about the kernel build process.
-kernel-doc-nano-HOWTO.txt
-	- outdated info about kernel-doc documentation.
 kdump/
 	- directory with mini HowTo on getting the crash dump code to work.
 doc-guide/

scripts/kernel-doc

@@ -48,7 +48,7 @@ Read C language source or header FILEs, extract embedded documentation comments,
 and print formatted documentation to standard output.
 
 The documentation comments are identified by "/**" opening comment mark. See
-Documentation/kernel-doc-nano-HOWTO.txt for the documentation comment syntax.
+Documentation/doc-guide/kernel-doc.rst for the documentation comment syntax.
 
 Output format selection (mutually exclusive):
   -docbook		Output DocBook format.