the directory README upgrade

Author: zhenwei-li

doc/description/directory/README.md

@@ -1,3 +1,37 @@
 # README
 
 this is dir modules.
+
+## describe
+
+This is a package component that simply handles directories and specific text.
+
+```bash
+NAME
+    common_dir
+
+FUNCTIONS
+    generate_complex_file_name(output_dir_name, file_name)
+        the generate complex file name
+
+    generate_complex_or_fmt_file_name(output_dir_name, file_name, fmt='%Y%m%d_%H%M%S')
+        the generate out complex or fmt file name
+
+    generate_file_name(output_dir_name, file_name)
+        the generate out file name
+
+    generate_file_name_only(output_dir_name, file_name)
+        the generate file name only
+
+    generate_fmt_file_name(output_dir_name, file_name, fmt='%Y%m%d_%H%M%S')
+        the generate out with fmt file name
+
+    mk_children_dir(output_dir_name, sub_dir_name)
+        the initialize children dir
+
+    mk_dir(output_dir_name)
+        the initialize global output dir
+
+    mk_output_dir(output_dir_name)
+        the initialize output dir
+```