Rename namespace to Tezmanian and prepare for Packagist

- Namespace Tez\Utils -> Tezmanian\Utils, package tez/* -> tezmanian/*
- Add keywords, homepage, authors and support metadata
- Drop VCS repositories (resolved via Packagist)
- Remove stale composer.lock, set license holder

src/Interpolate.php

@@ -2,7 +2,7 @@
 
 declare(strict_types=1);
 
-namespace Tez\Utils\Str;
+namespace Tezmanian\Utils\Str;
 
 final class Interpolate
 {