Make the "Template docs" tab be the default tab

[mgax]

When looking at a component in the pattern library, if the component has any docs, I'm liable to miss them, because they are hidden inside a tab.

Describe the solution you'd like

• Change the order of the tabs to make "Template docs" be the first.
• Consider renaming the tabs. They are currently named "Template source", "Template config" and "Template docs". I think "Template" is redundant; naming them "Source", "Sample data" and "Documentation" would work better.

Describe alternatives you've considered

I could override the pattern_library/index.html template in my project, but it seems like this change would benefit all users of django-pattern-library.

Additional context

My project is considering implementing Storybook on top of django-pattern-library because it places the documentation up front and centre. As an alternative, I'm exploring ways that django-pattern-library can be more useful out of the box.