Support .dict format

There are many free dictionaries with `.dict` format here: http://abloz.com/huzheng/stardict-dic/

It would be nice if we have support for it. To get the raw text dictionary:
- Install dictzip
- Run command: "dictunzip
- The database is `.dict` file.

Start by reviewing the repository's existing dictionary lookup flow and how external dictionary data is read; the issue does not name specific files or tests. Use the linked dictionary source and the provided dictunzip command to understand the raw .dict input, and consider the work complete when .dict dictionaries can be looked up through Helm.

Written by the indexing model from the issue text.