Spearhead: Update theme URL

spearhead/assets/sass/style.scss

@@ -1,6 +1,6 @@
 /*
 Theme Name: Spearhead
-Theme URI: https://github.com/Automattic/themes/root-child
+Theme URI: https://wordpress.com/theme/spearhead
 Author: Automattic
 Author URI: https://automattic.com/
 Description: Share your podcast with the world using Spearhead.

spearhead/style-rtl.css

@@ -1,6 +1,6 @@
 /*
 Theme Name: Spearhead
-Theme URI: https://github.com/Automattic/themes/root-child
+Theme URI: https://wordpress.com/theme/spearhead
 Author: Automattic
 Author URI: https://automattic.com/
 Description: Share your podcast with the world using Spearhead.

spearhead/style.css

@@ -1,6 +1,6 @@
 /*
 Theme Name: Spearhead
-Theme URI: https://github.com/Automattic/themes/root-child
+Theme URI: https://wordpress.com/theme/spearhead
 Author: Automattic
 Author URI: https://automattic.com/
 Description: Share your podcast with the world using Spearhead.