[FIX] invalid namespace

I was trying out the plugin, but bumped into the same error as mentioned in issue #2 . The fatal error was due to the invalid namespace `\Phile\Parser\Textile`, which should actually be `\Phile\Plugin\Phile\Textile\Parser` since Phile v1.x
Merge pull request #3 from Stijn-Flipper/patch-1

[FIX] invalid namespace