[libadwaita/wip/cdavis/gitignore-subprojects] gitignore: Ignore subproject checkout directories

[Christopher Davis <christopherdavis src gnome org>]

commit 3a998513d444b16ffd8cb0fdb601d3d0e29d63a6
Author: Christopher Davis <christopherdavis gnome org>
Date:   Wed Jun 23 13:41:32 2021 -0700

    gitignore: Ignore subproject checkout directories
    
    These directories, pulled in by the build system, should
    not be checked into our commit history. Adding them to the
    gitignore will prevent anyone from accidentally adding them.

 .gitignore | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/.gitignore b/.gitignore
index 826102bc..232c4925 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,4 +5,8 @@ _build
 .\#*
 build
 .buildconfig
-.flatpak-builder
\ No newline at end of file
+.flatpak-builder
+subprojects/sassc
+subprojects/libsass
+subprojects/gi-docgen
+