add support for Croatian

[gour]

Hello,

I did add "hr" to the adict-language-list as well as

 ("hr" "hrvatski" "croatian")

to the adict--guess-dictionary-cons and Croatian language was auto-detected for several files I tried with, but wonder what else would be required in order to have 'proper' support for Croatian language?

[To1ne]

Good question, I would like to added support for Dutch.

[To1ne]

Ahha, you also would need to have a list of words used to detect a language. e.g. https://github.com/nschum/auto-dictionary-mode/pull/14/files#diff-415e393816dbf067b6560545f56c9015R703