[gcc r13-6628] libstdc++: Refer to documentation hacking docs from Makefile

[gcc r13-6628] libstdc++: Refer to documentation hacking docs from Makefile

[Jonathan Wakely]

https://gcc.gnu.org/g:6ba33b188984badf0fc93c34af4bb640d611bd5c

commit r13-6628-g6ba33b188984badf0fc93c34af4bb640d611bd5c
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Mar 13 10:30:47 2023 +0000

    libstdc++: Refer to documentation hacking docs from Makefile
    
    libstdc++-v3/ChangeLog:
    
            * doc/Makefile.am: Add comment referring to documentation.
            * doc/Makefile.in: Regenerate.

Diff:
---
 libstdc++-v3/doc/Makefile.am | 2 ++
 libstdc++-v3/doc/Makefile.in | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/libstdc++-v3/doc/Makefile.am b/libstdc++-v3/doc/Makefile.am
index cc18b61cf55..8371441c62e 100644
--- a/libstdc++-v3/doc/Makefile.am
+++ b/libstdc++-v3/doc/Makefile.am
@@ -24,6 +24,8 @@ include $(top_srcdir)/fragment.am
 
 # Documentation Overview
 #
+# See ./xml/manual/documentation_hacking.xml for full details.
+#
 # There are two main input materials for libstdc++ documentation.
 # The first is the doxygen markup in libstdc++ sources, which is a
 # reference to the API. And the second is the manual, via docbook markup in
diff --git a/libstdc++-v3/doc/Makefile.in b/libstdc++-v3/doc/Makefile.in
index db5e81a7d60..21ad8557f7a 100644
--- a/libstdc++-v3/doc/Makefile.in
+++ b/libstdc++-v3/doc/Makefile.in
@@ -393,6 +393,8 @@ AM_CPPFLAGS = $(GLIBCXX_INCLUDES) $(CPPFLAGS)
 
 # Documentation Overview
 #
+# See ./xml/manual/documentation_hacking.xml for full details.
+#
 # There are two main input materials for libstdc++ documentation.
 # The first is the doxygen markup in libstdc++ sources, which is a
 # reference to the API. And the second is the manual, via docbook markup in