Added implementations of Runga kutta method along with test cases for Hacktoberfest contribution

[mapcrafter2048]

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Describe your change:

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new JavaScript files are placed inside an existing directory.
• All filenames should use the UpperCamelCase (PascalCase) style. There should be no spaces in filenames.
  Example:UserProfile.js is allowed but userprofile.js,Userprofile.js,user-Profile.js,userProfile.js are not
• All new algorithms have a URL in their comments that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.72%. Comparing base (9010481) to head (7214c0a).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1710      +/-   ##
==========================================
+ Coverage   84.65%   84.72%   +0.06%     
==========================================
  Files         378      379       +1     
  Lines       19744    19824      +80     
  Branches     2951     2955       +4     
==========================================
+ Hits        16715    16795      +80     
  Misses       3029     3029              

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[raklaptudirm]

Creating new variables here is unnecessary as xStart and yStart are never used later. Renaming the variables to x and y and just using them would be better. This would also allow you to use the object shorthand syntax:

const points = [{ x, y }] // Line 55
points.push({ x, y }) // Line 76