Level 1 (Shell): Add basic bash syntax examples

[iamdevdhanush]

Add basic shell scripting examples:

• variables
• echo
• if/else
• loops

Location: level-1-shell-scripting/basics/

[wooddang-gachon]

Hi! I'd like to work on this issue. 🙋‍♂️

[iamdevdhanush]

@wooddang-gachon Feel free to continue its open!!

[wooddang-gachon]

Hi! I’ve submitted a pull request addressing this issue.
Please let me know if you’d like any changes or improvements. Thanks!