feat: add a simple file

[realstealthninja]

Description of Change

Checklist

• Added description of change
• Added file name matches File name guidelines
• Added tests and example, test must pass
• Added documentation so that the program is self-explanatory and educational - Doxygen guidelines
• Relevant documentation/comments is changed or added
• PR title follows semantic commit guidelines
• Search previous suggestions before making a new one, as yours may be a duplicate.
• I acknowledge that all my contributions will be made under the project's license.

Notes:

[cpp-keeper]

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[cpp-keeper]

File should begin with a comment header

/**
 * @file
 * @brief Add one-line description here. Should contain a Wikipedia
 * link or another source explaining the algorithm/implementation.
 * @details
 * This is a multi-line
 * description containing links, references,
 * math equations, etc.
 * @author [Name](https://github.com/handle)
 * @see related_file.cpp, another_file.cpp
 */