doc: add limitations section

README.md

@@ -66,6 +66,16 @@ twind -c tailwind.prod.js
     -h, --help           Displays this message
 ```
 
+## Limitations
+
+@twind/cli is a utility that can greatly help in some cases, however in practice it can also:
+
+- the grouping feature is currently **not** supported
+- yield "false positives" (i.e. detect TailwindCSS classes / selectors that are not actually used, due to broad string-based / regular expression search)
+- give false impressions (e.g. class names generated by Twind at runtime via `css()`, `apply()` and `style()` cannot possibly be computed via static code analysis, so the CLI-generated stylesheet is likely incomplete in most realistic use-cases).
+
+Please see [issue #1](https://github.com/tw-in-js/twind-cli/issues/1) for more details.
+
 ## License
 
 [MIT](https://github.com/tw-in-js/cli/blob/main/LICENSE)