Add file generator

This MR is adding a file generator script that will generate file with a provided number of lines and commits.

For each generated line, it will create separate commit.

It will push the created file to your repo in the end.

• full_path: path to the file we would like to generate inside existing git repository
• number_of_lines: number of lines/commits to be generated

Run with:

ruby generate_file_with_commits.rb :full_path :number_of_lines