Added continuation indent to editorconfig

Adding our default cont' indent to editorconfig.

Change-Id: Id1d848d5959ced9592382bf9a12d7ffc8152dce3
diff --git a/.editorconfig b/.editorconfig
index 1f149cf..cb18523 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -9,3 +9,4 @@
 charset = utf-8
 indent_style = space
 indent_size = 2
+continuation_indent_size = 4