[gimp] devel-docs: fix autotools dist rules.

[Jehan <jehanp src gnome org>]

commit 84d298d4d3cd1697f01bcaa3974595587ee5fab9
Author: Jehan <jehan girinstud io>
Date:   Mon Jan 24 15:37:10 2022 +0100

    devel-docs: fix autotools dist rules.
    
    Since I removed some files and forgot to change these rules. Though I
    actually wonder if this still makes sense to distribute all these files
    within the tarball anymore. It made sense in the way software was
    distributed 20 years ago, but nowadays people who want to develop would
    clone the git repo not get a tarball. We'll see.

 devel-docs/Makefile.am | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
---
diff --git a/devel-docs/Makefile.am b/devel-docs/Makefile.am
index 178c53f1de..f31d12e068 100644
--- a/devel-docs/Makefile.am
+++ b/devel-docs/Makefile.am
@@ -7,7 +7,7 @@ SUBDIRS = \
        performance-logs
 
 EXTRA_DIST = \
-       README                          \
+       README.md                       \
        contexts.txt                    \
        debug-plug-ins.txt              \
        exif-handling.txt               \
@@ -16,8 +16,6 @@ EXTRA_DIST = \
        libtool-instructions.txt        \
        parasites.txt                   \
        release-howto.txt               \
-       structure.xml                   \
-       submitting-patches.txt          \
        tagging.txt                     \
        ui-framework.txt                \
        undo.txt                        \