[babl] docs: update meson.build

[Øyvind "pippin" Kolås <ok src gnome org>]

commit f1fdb86de56fb9b3066bf67b08f664a310181955
Author: Øyvind Kolås <pippin gimp org>
Date:   Mon Jul 22 16:11:07 2019 +0200

    docs: update meson.build

 docs/meson.build | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/docs/meson.build b/docs/meson.build
index bc43822..7dba677 100644
--- a/docs/meson.build
+++ b/docs/meson.build
@@ -54,13 +54,13 @@ index_html = custom_target('index.html',
   build_by_default: true,
 )
 
-Vocabulary_html = custom_target('Vocabulary.html',
+Reference_html = custom_target('Reference.html',
   input : [
-    'Vocabulary-static.html',
+    'Reference-static.html',
     'toc',
     index_html_tmp,
   ],
-  output: [ 'Vocabulary.html', ],
+  output: [ 'Reference.html', ],
   command: [
     env_bin,
     'cp', '@INPUT0@', '@OUTPUT@',