User Story: Preference section

[mikael-johnsson]

As a user, I can easily find and read the preference section so that I can use the extension

Acceptance Criteria:

• The extension symbol is easy to read as this extension
• The menu is opened when clicking the extension symbol
• The menu contains all the tools

Tasks:

• [x] Create a html-list in the index-file
• [ ] Add styling to the list
• [x] Connect the list items to the corresponding Javascript-function