Documenting that parents are not supported

README.md

@@ -265,6 +265,7 @@ Pull requests to solve the following issues would be helpful.
 
 * Dotted names are supported but only for associative arrays (Bash 4).  See [`demo/associative-arrays`](demo/associative-arrays) for an example.
 * There's no "top level" object, so `echo '{{.}}' | ./mo` does not do anything useful.  In other languages you can say the data for the template is a string and in `mo` the data is always the environment.  Luckily this type of usage is rare and `{{.}}` works great when iterating over an array.
+* [Parents](https://mustache.github.io/mustache.5.html#Parents), where a template can override chunks of a partial, are not supported.
 * HTML encoding is not built into `mo`.  `{{{var}}}`, `{{&var}}` and `{{var}}` all do the same thing.  `echo '{{TEST}}' | TEST='<b>' mo` will give you "`<b>`" instead of "`&gt;b&lt;`".