fix(man): make sure manpage is used in npx bin

Author: zkat

bin/package.template.json

@@ -3,6 +3,7 @@
   "description": "execute npm package binaries",
   "main": "index.js",
   "bin": "index.js",
+  "man": "./npx.1",
   "files": [
     "./*.js",
     "./npx.1"