Create find-the-maximum-sum-of-node-values.cs

[rezzcode]

Description

Leetcode cs solution

Fixes #(issue_no)

• Issue_no: <insert your issue no here>
• Not applicable

Type of change

Choosing one or more options from the following as per the nature of your Pull request.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Documentation Update

Checklist:

Please tick all the boxes that are fulfilled by your Pull Request.

• My code beats 50% + of the users, will 💙 to hear this.
• I have named my files and folder, according to this project's guidelines.
• My code follows the style guidelines of this project and uptodate with the current trends.
• I have commented on my code, particularly in hard-to-understand areas and included the time complexity O(n).
• I have created a helpful and easy to understand README.md especialy when you created a new directory.
• My changes do not produce any warnings.

[the1Riddle]

LGTM