Add render_patterns management command for static export and automated render check (#17, #18)

[thibaudcolas]

Addresses #17 and #18.

./manage.py render_patterns

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[bcdickinson]

One actual point, and one minor semantic point about stdout vs. stderr, but otherwise LGTM.

[thibaudcolas]

I’ve fixed what you reported @bcdickinson, and additionally added an argument to configure whether the rendered templates should be wrapped in the base template or not.

I’ll now merge this as-is – I think it’s good to go apart from missing documentation, which I’ve intentionally removed but will add as a separate PR.