docs: update README.md

README.md

@@ -1,3 +1,9 @@
 ## datepicker
 
-datepicker
+之前版本，可查看`tag`v1.0.0
+
+```shell
+$ git clone https://github.com/Rynxiao/datepicker.git
+$ git tag
+$ git checkout v1.0.0
+```