README: Fix title

Make sure package.sublimetext.io displays correct information.

Note: It can't resolve the wrapped image link.

Author: deathaxe

README.md

@@ -1,4 +1,6 @@
-# [![A File Icon][img-logo]][downloads]
+# A File Icon
+
+![preview][img-logo]
 
 [![Star on GitHub][img-stars]][stars]
 [![Join the chat at Sublime Forum][img-forum]][forum]