Update usage instructions to source hooks (#127)

Author: paulodiovani

USAGE.md

@@ -109,7 +109,7 @@ tinty_source_shell_theme() {
     while read -r script; do
       # shellcheck disable=SC1090
       . "$script"
-    done < <(find "$tinty_data_dir" -maxdepth 1 -type f -name "*.sh" -newer "$newer_file")
+    done < <(find "$tinty_data_dir" -maxdepth 1 -type f -o -type l -name "*.sh" -newer "$newer_file")
 
     unset tinty_data_dir
   fi