twelve-days lacks a Text example

[petertseng]

twelve-days is one of the exercises for which this Haskell language track makes a recommendation to use Data.Text instead of String.

However, it lacks a Text example solution, which means that it's possible that we might accidentally make the tests fail to compile with a Text-based solution, and not notice.

To avoid accidentally breaking the tests, this track should add a Text example solution. See how other exercises do it in https://github.com/exercism/haskell/tree/main/exercises/practice/acronym/.meta/examples/success-text, or any of the other exercises with Text example solutions:

exercises/practice/acronym/.meta/examples/success-text
exercises/practice/atbash-cipher/.meta/examples/success-text
exercises/practice/bob/.meta/examples/success-text
exercises/practice/diamond/.meta/examples/success-text
exercises/practice/etl/.meta/examples/success-text
exercises/practice/isogram/.meta/examples/success-text
exercises/practice/pangram/.meta/examples/success-text
exercises/practice/pig-latin/.meta/examples/success-text
exercises/practice/raindrops/.meta/examples/success-text
exercises/practice/resistor-color-trio/.meta/examples/success-text
exercises/practice/rotational-cipher/.meta/examples/success-text

Please leave the existing success-standard twelve-days in place when adding this new success-text example.