.gitignore: Ignore more generated files

Signed-off-by: Simon McVittie <smcv@collabora.com>

.gitignore

@@ -32,6 +32,7 @@ stamp-*
 gtk-doc.make
 flatpak
 flatpak-*.tar.xz
+/flatpak-1.*/
 flatpak-session-helper
 flatpak-portal
 flatpak-validate-icon

doc/reference/.gitignore

@@ -2,9 +2,12 @@ html/
 xml/
 *.stamp
 *.bak
+/dbus-*.xml
+/flatpak.actions
 flatpak-decl-list.txt
 flatpak-decl.txt
 flatpak-overrides.txt
+flatpak-scan.c
 flatpak-undeclared.txt
 flatpak-undocumented.txt
 flatpak-unused.txt