xdebugPhpFpm permission denied fix (#587)

* xdebugPhpFpm permission denied fix

* xdebugPhpFpm might not have execution access when cloned. This
addition to readme helps tell the user why he got Permission Denied and
what can be done to fix it.

* Fix doesn't spelling, remove newline

* This is fixup for `38e26c3`.

README.md

@@ -794,6 +794,7 @@ To control the behavior of xDebug (in the `php-fpm` Container), you can run the
 - Start xDebug by default: `./xdebugPhpFpm start`.
 - See the status: `./xdebugPhpFpm status`.
 
+Note: If `./xdebugPhpFpm` doesn't execute and gives `Permission Denied` error the problem can be that file `xdebugPhpFpm` doesn't have execution access. This can be fixed by running `chmod` command  with desired access permissions.