README: Recommend Interfacer be put in the services folder

This makes more logic sense as while it is technically an APK, we intend for it to be a service.

Change-Id: I5e479a668aa07d4c3eb9dbff16b5ec9e25b34fc0
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
diff --git a/README.md b/README.md
index 0a24440..1d8dbf9 100644
--- a/README.md
+++ b/README.md
@@ -15,4 +15,4 @@
 
 Don't forget to add the project path in your AOSP manifest:
 
-    <project path="packages/apps/ThemeInterfacer" name="substratum/interfacer" remote="github" revision="n-rootless" />
+    <project path="packages/services/ThemeInterfacer" name="substratum/interfacer" remote="github" revision="n-rootless" />