docs(copy-models): add README for using copy-models script (#2358)

Author: trivikr

scripts/copy-models/README.md

@@ -0,0 +1,20 @@
+# How to copy models
+
+## Prerequisite
+
+- Node.js version >= 12.
+- Ensure that aws-models directory is updated.
+
+## Options
+
+```
+  --version     Show version number                                    [boolean]
+  -m, --models  The path to directory with aws-models.       [string] [required]
+  --help        Show help                                              [boolean]
+```
+
+## Examples
+
+- Copy models from aws-models:
+
+  `yarn copy-models -m path/to/aws-models`