Add an .editorconfig file

closes #19793

.editorconfig

+# http://editorconfig.org
+
+root = true
+
+[*.hs]
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true
+insert_final_newline = true
+charset = utf-8
+end_of_line = lf
+
+[Makefile]
+indent_style = tab