Dictionary support inconsistency in README #142

The README defines dictionary_key, dictionary_entry, and dictionary in its EBNF grammar and allows dictionaries as attribute values:

attribute = name, "=", literal | dictionary

However, the Attributes section states “Hashes or dictionaries are not supported” and marks a dictionary-valued attribute as invalid.

The Octopus OCL reference also explicitly documents properties as a dictionary using properties = { ... }.

Please clarify dictionary support and align the README’s grammar, explanation, and examples.