doc: improve grammar in API description

PR-URL: #40959
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/tls.md

@@ -1477,8 +1477,8 @@ Verifies the certificate `cert` is issued to `hostname`.
 Returns {Error} object, populating it with `reason`, `host`, and `cert` on
 failure. On success, returns {undefined}.
 
-This function can be overwritten by providing alternative function as part of
-the `options.checkServerIdentity` option passed to `tls.connect()`. The
+This function can be overwritten by providing an alternative function as the
+`options.checkServerIdentity` option that is passed to `tls.connect()`. The
 overwriting function can call `tls.checkServerIdentity()` of course, to augment
 the checks done with additional verification.