Add editorconfig

Introduced by cotes2020#119

Author: cotes2020

.editorconfig

@@ -0,0 +1,11 @@
+root = true
+
+[*]
+charset = utf-8
+# 2 space indentation
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true
+# Unix-style newlines with a newline ending every file
+end_of_line = lf
+insert_final_newline = true