[gtkmm] Docs: Allow @newin with micro version, @newin{1,2,3}

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 622cc0ebebc5af29aee8d5d0be280507c8e77eda
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Tue Dec 11 20:28:10 2018 +0100

    Docs: Allow @newin with micro version, @newin{1,2,3}

 docs/reference/Doxyfile.in | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/docs/reference/Doxyfile.in b/docs/reference/Doxyfile.in
index 682bec79..00d756e0 100644
--- a/docs/reference/Doxyfile.in
+++ b/docs/reference/Doxyfile.in
@@ -38,7 +38,8 @@ MULTILINE_CPP_IS_BRIEF = NO
 INHERIT_DOCS           = YES
 SEPARATE_MEMBER_PAGES  = NO
 TAB_SIZE               = 8
-ALIASES                = "newin{2}=\xrefitem since_\1_\2 \"Since @PACKAGE_NAME@ \1.\2\" \"New API in 
@PACKAGE_NAME@ \1.\2\""
+ALIASES                = "newin{2}=\xrefitem since_\1_\2 \"Since @PACKAGE_NAME@ \1.\2\" \"New API in 
@PACKAGE_NAME@ \1.\2\"" \
+                         "newin{3}=\xrefitem since_\1_\2_\3 \"Since @PACKAGE_NAME@ \1.\2.\3\" \"New API in 
@PACKAGE_NAME@ \1.\2.\3\""
 TCL_SUBST              =
 OPTIMIZE_OUTPUT_FOR_C  = NO
 OPTIMIZE_OUTPUT_JAVA   = NO