Added scoop-home command

`scoop home <app>` opens the homepage for the given app

libexec/scoop-home.ps1

@@ -0,0 +1,23 @@
+# Usage: scoop home <app>
+# Summary: Opens the app homepage
+param($app)
+
+. "$psscriptroot\..\lib\core.ps1"
+. "$psscriptroot\..\lib\help.ps1"
+. "$psscriptroot\..\lib\manifest.ps1"
+. "$psscriptroot\..\lib\buckets.ps1"
+
+if($app) {
+    $manifest, $bucket = find_manifest $app
+    if($manifest) {
+        if([string]::isnullorempty($manifest.homepage)) {
+            abort "could not find homepage in manifest for '$app'"
+        }
+        start $manifest.homepage
+    }
+    else {
+        abort "could not find manifest for '$app'"
+    }
+} else { my_usage }
+
+exit 0