Added new sorting algorithm, middle sort

[dja322]

Description of Change

Add a new algorithm called middle sort, which starts in the middle of an array and sorts it from the center element(s) outwards until the edges of the array are reached, at which point the array is sorted.

References

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: Add a new sorting algorithm called middle sort