Create .editorconfig

Adding a config for editors as in the Firebot repo, to keep it the same.

Author: brumoen

.editorconfig

@@ -0,0 +1,10 @@
+root = true
+
+[*.{js,ts,tsx,css,scss,sass,mjs}]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = false
+indent_style = space
+indent_size = 4
+trim_trailing_whitespace = true
+max_line_length = 120