Update reverse.rs

[dev-priyanshu15]

1. macro_rules! test_cases: This macro is designed to reduce repetition by defining multiple test cases at once. It takes a list of test names and test case tuples ((input, expected)).
2. $name:ident: The test function name. For example, test_simple_palindrome is generated as the test function name.
3. $test_case:expr: This represents a tuple of (input, expected) for each test.
4. Generated Test Functions: Each entry inside test_cases! expands into a separate test function. For example, the test_simple_palindrome macro expands into a function that tests if reversing "racecar" returns "racecar"

Pull Request Template

Description

Please include a summary of the change and which issue (if any) is fixed.
A brief description of the algorithm and your implementation method can be helpful too. If the implemented method/algorithm is not so
well-known, it would be helpful to add a link to an article explaining it with more details.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• I ran bellow commands using the latest version of rust nightly.
• I ran cargo clippy --all -- -D warnings just before my last commit and fixed any issue that was found.
• I ran cargo fmt just before my last commit.
• I ran cargo test just before my last commit and all tests passed.
• I added my algorithm to the corresponding mod.rs file within its own folder, and in any parent folder(s).
• I added my algorithm to DIRECTORY.md with the correct link.
• I checked COUNTRIBUTING.md and my code follows its guidelines.

Please make sure that if there is a test that takes too long to run ( > 300ms), you #[ignore] that or
try to optimize your code or make the test easier to run. We have this rule because we have hundreds of
tests to run; If each one of them took 300ms, we would have to wait for a long time.

[dev-priyanshu15]

dont forget to add hacktoberfest-accepted label

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.38%. Comparing base (1ef9bcb) to head (d7e7fef).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #822   +/-   ##
=======================================
  Coverage   95.38%   95.38%           
=======================================
  Files         312      312           
  Lines       22645    22645           
=======================================
  Hits        21601    21601           
  Misses       1044     1044           

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[sozelfist]

Please close these spammed PRs. Please take a look at the CONTRIBUTING guidelines. If something like this happens one more time, we would like to consider blocking you from the repo.

Last but not least, we welcome contributors to contribute to developing the repo but not PR spammer just for Hacktoberfest events.

[sozelfist]

Please close this one too, #818.

[vil02]

@dev-priyanshu15: I do not see the purpose of this PR.