Improvements page redesign

Please don't merge this yet! :) Text and button links in each of the requirements expanders on this page are still static, they need linking to real data.

- [ ] The Raspberry coloured "I don't understand" button needs to link to the equivalent question's "Ask for help with this question" URL

- [ ] The block of text to the left of the two buttons is static now but should be populated with the explanatory text from the equivalent question (which appears inside the light blue area when you hover over a question on the certificates page)