[librsvg/wip/davidk/gtk-doc-configure] docs: Install to the correct directory that Devhelp expects

[Federico Mena Quintero <federico src gnome org>]

commit 12f49be936464faacf719f354adfd2a01aa26d6c
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri May 13 13:43:12 2022 -0500

    docs: Install to the correct directory that Devhelp expects
    
    The convention is $(datadir)/doc/ModuleNamespace-api_version -
    so, $(datadir)/doc/Rsvg-2.0 for librsvg.

 doc/Makefile.am | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/doc/Makefile.am b/doc/Makefile.am
index d13f32198..1dcc4133f 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -21,11 +21,14 @@ build.stamp: $(DOCS_SRC) $(HEADERS_WITH_DOCS) $(GIR_FILE)
 clean-local:
        rm -rf Rsvg-2.0
 
+# This is the devhelp convention for documentation paths; it will look for the .devhelp file there
+DOC_INSTALL_DIR=$(DESTDIR)/$(datadir)/doc/Rsvg-2.0
+
 install-data-local: build.stamp
-       $(MKDIR_P) $(DESTDIR)/$(docdir)/Rsvg-2.0
-       for f in Rsvg-2.0/*; do $(INSTALL_DATA) $$f $(DESTDIR)/$(docdir)/Rsvg-2.0; done
+       $(MKDIR_P) $(DOC_INSTALL_DIR)
+       for f in Rsvg-2.0/*; do $(INSTALL_DATA) $$f $(DOC_INSTALL_DIR); done
 
 uninstall-local:
-       rm -rf $(DESTDIR)/$(docdir)/Rsvg-2.0
+       rm -rf $(DOC_INSTALL_DIR)
 
 all-local: build.stamp