Update docs and add links for 28th meetup

[o-samaras]

• Adds contributing.md
• Adds links to 28th meetup presentation and resources in docs directory
• Moves tool information from main readme.md to docs directory

[vagelisp]

@o-samaras, Φοβερός !!!! 👏🏻 👏🏻 👏🏻