new_module: Modify new_module and templates for Ansible 2.14

ansible-test with ansible-2.14 is adding a lot of new tests to ensure
that the documentation section and the agument spec is complete.

To aid the creation of new_modules that follow these rules, the
'new_module' script and its templates were modified to use the new
ansible-test rules. The 'new_module' script now requires a new
argument, github_user, and the code templates provide the required
fields (like 'type' and 'elements') to the provide examples.