Added Hexadecimal to String Conversor

[lcsjunior]

Description of Change

I've transcribed one of my Hexadecimal to String Conversor and vice versa that I use in my ESP32 Projects with the intention of participating in Hacktoberfest and future contributions. Please consider accepting my code.

This converter consists of converting a hexadecimal to a string and vice versa.

References

None

Checklist

• Added description of change
• Added file name matches File name guidelines
• Added tests and example, test must pass
• 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: