[doc] Fix warning: Section has no title and no file
Move the private macros to the hb-common section, instead of a file-less
one.
diff --git a/docs/harfbuzz-sections.txt b/docs/harfbuzz-sections.txt
index c207901..fd07b81 100644
--- a/docs/harfbuzz-sections.txt
+++ b/docs/harfbuzz-sections.txt
@@ -1,11 +1,4 @@
<SECTION>
-<SUBSECTION Private>
-HB_H_IN
-HB_OT_H_IN
-HB_AAT_H_IN
-</SECTION>
-
-<SECTION>
<FILE>hb-aat-layout</FILE>
HB_AAT_LAYOUT_NO_SELECTOR_INDEX
hb_aat_layout_feature_type_t
@@ -184,6 +177,10 @@
HB_EXTERN
HB_DEPRECATED
HB_DEPRECATED_FOR
+<SUBSECTION Private>
+HB_H_IN
+HB_OT_H_IN
+HB_AAT_H_IN
</SECTION>
<SECTION>
