Stack implementation using linked list (template)

# Aim

- Creating a stack using a linked list

# Details

- Create a stack data structure using the linked list and the template feature of C++ so that data type of stack is decided at object creation.

### Programming language

- [ ] C
- [x] C++
- [ ] Java
- [ ] Python

The issue names no source file, test, or entry point. Inspect the repository's C++ data-structure layout first, then identify where a linked-list stack belongs; done means a stack whose element type is selected through a C++ template and whose implementation matches the project's conventions.

Written by the indexing model from the issue text.