Add Services Section

I've been doing freelance for the last 3 years and have recently started using Upwork to get clients. While I've been using that the last month or so I realise I don't have many a section where I can point to stuff that I have done.

I need to add a Services section in order to be able to paste in a link to examples / portfolios of things I've done in my professional life. Not sure what form this is going to take but more than likely it is going to be nested via:

Services -> Email -> Example 1
                  -> Example 2
         -> WordPress -> Example 1
                      -> Example 2

And so on...