Complete the install note with the "how to change the design" part

[annelisebouyer]

The idea is to answer to these questions:

• What parts of the app are designed with extension and modification in mind?
  • How is the design of the app specified?
    • How robust is the "stylesheet"? Can you tamper with it without breaking the app?
  • How are the views of individual "stories" (database items) generated?
  • What are the templates for the various pages of the app like? How much can you change in them?