Exercise 42: Block Structure in C ("block_structure") ("Chapter 4.8")

[danwritecode]

Looking for help creating exercise:
Topic: Block Structure in C
Exercise Directory Name: block_structure

Note: For Directory Name, refer to the exercises directory to find the correct number to use. It should be close to the number in the issue title but may be slightly off.

Refer to "The C Programming Language" book, Chapter 4.8 for more information.

Contribution instructions: https://github.com/danwritecode/clings?tab=readme-ov-file#contributions