Update CONTRIBUTING.md
Update CONTRIBUTING.md

Numerous updates were made to the CONTRIBUTING.md file in order to make the project more welcoming to new FOSS contributors. A number of inline links were added to facilitate learning of version control jargon.
natanfelles/CodeIgniter4,lonnieezell/CodeIgniter4,jim-parry/CodeIgniter4,bcit-ci/CodeIgniter4,lonnieezell/CodeIgniter4,kenjis/CodeIgniter4,samsonasik/CodeIgniter4,natanfelles/CodeIgniter4,ytetsuro/CodeIgniter4,ytetsuro/CodeIgniter4,butane/CodeIgniter4,kenjis/CodeIgniter4,natanfelles/CodeIgniter4,jim-parry/CodeIgniter4,natanfelles/CodeIgniter4,kenjis/CodeIgniter4,butane/CodeIgniter4,kenjis/CodeIgniter4,gustavojm/CodeIgniter4,gustavojm/CodeIgniter4,ytetsuro/CodeIgniter4,ytetsuro/CodeIgniter4,lonnieezell/CodeIgniter4,gustavojm/CodeIgniter4,samsonasik/CodeIgniter4,bcit-ci/CodeIgniter4,butane/CodeIgniter4,butane/CodeIgniter4,kenjis/CodeIgniter4,jim-parry/CodeIgniter4,bcit-ci/CodeIgniter4,jim-parry/CodeIgniter4,natanfelles/CodeIgniter4,butane/CodeIgniter4,butane/CodeIgniter4,samsonasik/CodeIgniter4,lonnieezell/CodeIgniter4,gustavojm/CodeIgniter4,jim-parry/CodeIgniter4,lonnieezell/CodeIgniter4,samsonasik/CodeIgniter4,jim-parry/CodeIgniter4,lonnieezell/CodeIgniter4,samsonasik/CodeIgniter4,ytetsuro/CodeIgniter4,samsonasik/CodeIgniter4,bcit-ci/CodeIgniter4,natanfelles/CodeIgniter4,bcit-ci/CodeIgniter4,ytetsuro/CodeIgniter4