Add continuation indent to editorconfig

Without this setting IntelliJ indents continued lines only one level
instead of two.

Author: cboehme

.editorconfig

@@ -23,6 +23,7 @@ insert_final_newline=true
 trim_trailing_whitespace=true
 indent_style=space
 indent_size=4
+continuation_indent_size=8
 
 [{*.yml,*.yaml}]
 indent_style=space