[Training] Add training feedback forms to the site

The UX team has prepared 2 feedback forms for trainers to help us gather feedback. One is for the trainer, and the other is for the participants. More info at tpo/ux/research#61 (closed)

To provide localized forms, we will add them to the community portal.

I feel the best thing will be to add them in a specific place under the training section, and @nah has promised a text about how we really need this input because we dont spy on our users and it will make Tor better etc.