add permutations function

[l0ginp]

Please check all that apply.

This PR is for:

• Algorithm
• Cheatsheet
• Resource
• Other

Title for the Algorithm/Cheat-Sheet/Resource: [Title here]

Programming Language: [Language here]

• Have you implemented it on your local machine or any online compiler?
• There is the main( ) function to run the program and all the inputs which are being taken are clearly printed on the console or well commented in the file.
• Filename is self-explanatory or there is Readme.md file explaining the necessary details of the algorithm.

P.S. Failing to update the PR in 10 days on requested changes will be marked outdated and closed.

[starkblaze01]

LGTM,
since it's your first PR here marking as accepted for hacktoberfest also. Further PRs are most welcome but to be specific to Hacktoberfest acceptance will require some more quality contribution which will help the community as sorting algorithms are easily available. Also, you can use 'x' in place of '/' to ensure the check marks

[l0ginp]

LGTM, since it's your first PR here marking as accepted for hacktoberfest also. Further PRs are most welcome but to be specific to Hacktoberfest acceptance will require some more quality contribution which will help the community as sorting algorithms are easily available. Also, you can use 'x' in place of '/' to ensure the check marks

done, change 'x' to '/'