[gtksourceview] subprojects: add gitignore

[Christian Hergert <chergert src gnome org>]

commit 68f636a88915f7d12f2c9c2894a2f6a42034eb33
Author: Christian Hergert <chergert redhat com>
Date:   Wed Feb 2 19:32:35 2022 -0800

    subprojects: add gitignore

 subprojects/.gitignore | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
---
diff --git a/subprojects/.gitignore b/subprojects/.gitignore
new file mode 100644
index 00000000..fca211cb
--- /dev/null
+++ b/subprojects/.gitignore
@@ -0,0 +1,16 @@
+cairo/
+fontconfig/
+freetype/
+fribidi/
+gdk-pixbuf/
+gi-docgen/
+glib/
+gperf/
+gtk/
+harfbuzz/
+libffi/
+libsass/
+pango/
+pixman/
+sassc/
+wayland/