docs: clarify opts_extend

README.md

@@ -70,7 +70,7 @@
     },
 
     -- default list of enabled providers defined so that you can extend it
-    -- elsewhere in your config, without redefining it, via `opts_extend`
+    -- elsewhere in your config, without redefining it, due to `opts_extend`
     sources = {
       default = { 'lsp', 'path', 'snippets', 'buffer' },
       -- optionally disable cmdline completions