Coding style change for project_euler problem 36 and 35 (#3062)

* add problem url. Add typehint, default value and doctest

* run black

* add project url. add solution function for problem 35

* add space between imports on problem 35

* Update sol1.py

* Update sol1.py

Co-authored-by: Dhruv <dhruvmanila@gmail.com>