Created problem_35 in project_euler (#2309)

* Create __init__.py

* Update __init__.py

* Add files via upload

* Update sol1.py

* Update sol1.py to include type hints

* Update CONTRIBUTING.md to fix typo

* Update CONTRIBUTING.md

* Update project_euler/problem_35/sol1.py

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update project_euler/problem_35/sol1.py

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update project_euler/problem_35/sol1.py

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update project_euler/problem_35/sol1.py

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update project_euler/problem_35/sol1.py

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update project_euler/problem_35/sol1.py

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update project_euler/problem_35/sol1.py

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update sol1.py

* Update sol1.py

* Update sol1.py

* Fix the print(f"string")

Co-authored-by: Christian Clauss <cclauss@me.com>