Describe your change:

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

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• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
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• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
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Description

This PR adds the Base62 encoding and decoding algorithm. Base62 is a positional numeral system that uses 62 as its base, consisting of alphanumeric characters (0-9, a-z, A-Z). It is widely used for URL shortening and generating compact, human-readable identifiers.

Reference: Base62 - Wikipedia