Adding main to package.json

package.json

@@ -5,6 +5,7 @@
   "description": "JavaScript implementations of standard and secure cryptographic algorithms.",
   "keywords": [ "crypto", "md5", "sha1" ],
   "author": "Irakli Gozalishvili <[email protected]>",
+  "main": "sha1.js",
   "repository": {
     "type": "git",
     "url": "git://github.com/Gozala/crypto.git",