Describe your change:

This pull request introduces a new algorithm, reverse_array, which reverses a list of elements in-place using a two-pointer technique. This is a fundamental and memory-efficient method for array reversal.

The implementation is placed in the arrays directory and includes:

• Clear, descriptive function and variable names.
• Full type hinting for parameters and return values.
• A comprehensive docstring explaining the algorithm's logic.
• Extensive doctests to ensure correctness for various edge cases (e.g., empty lists, single-element lists, lists with odd/even lengths).

• 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?

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 Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".