Clean up redundant and outdated EditorConfig rules

Author: Alhadis

.editorconfig

@@ -4,13 +4,10 @@ root = true
 charset = utf-8
 end_of_line = lf
 insert_final_newline = true
-trim_trailing_whitespace = true
+trim_trailing_whitespace = false
 indent_style = tab
 indent_size = 4
 
-[*.{md,php}]
-trim_trailing_whitespace = false
-
-[*.{yml,reek,rviz,yaml}]
+[*.el]
 indent_style = space
-indent_size = 4
+indent_size = 2