Add .editorconfig

.editorconfig

@@ -0,0 +1,21 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 4
+
+# Tab indentation (no size specified)
+[Makefile]
+indent_style = tab
+
+# Indentation override for all JS under lib directory
+[*.{yaml}]
+indent_size = 2