Adds better default permissions

- Adds three new permission groups for easier setup
- Sets better default permissions
- Updates and prettifies some documentation
- Renames the silent portal option to quiet

src/main/java/net/knarcraft/stargate/utility/PortalFileHelper.java

@@ -138,7 +138,7 @@ public final class PortalFileHelper {
         builder.append(options.isNoNetwork()).append(':');
         builder.append(options.isRandom()).append(':');
         builder.append(options.isBungee()).append(':');
-        builder.append(options.isSilent()).append(':');
+        builder.append(options.isQuiet()).append(':');
         builder.append(options.hasNoSign());
     }