adding the fibonacci series to the Recursion package

[MohamedBoukthir]

• [x] I have read CONTRIBUTING.md.
• [x] This pull request is all my own work -- I have not plagiarized it.
• [x] All filenames are in PascalCase.
• [x] All functions and variable names follow Java naming conventions.
• [x] All new algorithms have a URL in their comments that points to Wikipedia or other similar explanations.
• [x] All new code is formatted with clang-format -i --style=file path/to/your/file.java

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 60.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 73.46%. Comparing base (df0c997) to head (123f683).

Files with missing lines	Patch %	Lines
...a/com/thealgorithms/Recursion/FibonacciSeries.java	60.00%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #6079 +/- ## ========================================= Coverage 73.46% 73.46% - Complexity 5096 5099 +3 ========================================= Files 657 658 +1 Lines 17632 17637 +5 Branches 3394 3394 ========================================= + Hits 12953 12957 +4 - Misses 4176 4178 +2 + Partials 503 502 -1 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.