chore: update abs function

[ridge-kimani]

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Describe your change:

• Updates the abs algorithm to use Maths.abs function which in turn makes the function run faster.
• Update an algorithm

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}.

[appgurueu]

Sorry, but the purpose of this repo is to show how one would implement these, not how to use the standard library (that said, abs is trivial and not useful given its redundancy with the stdlib and thus wouldn't be accepted if it were to be PR'd today).