Implement task 2 from block 3 (castles) of homework located at https://hackmd.io/@mtb49Ag9TOmTeG0qf_6Fwg/BkcpMch44

Implement Ord instance for newtype below.

It should follow the described semantics:

1. If both strings being compared start from a digit symbol (0..9), read numeric prefixes and compare strings by these prefixes. If both strings start from the same number (e.g. 01aba and 1caba), comparison is performed by rest of string characters case-insensitive
2. Otherwise, compare two strings case-insensitive

When launched from ghci, following results will be printed.

Explain the difference in calls (why one call returns while other goes into infinite loop):

> sumAndLogD [8] (BoxD 2)
Just 3.0

> sumAndLog [8] (Box 2)
Just 3.0

> sumAndLog [8 -10] loop
Nothing

> sumAndLogD [8 -10] loop
{.. infitinte loop ..}