fix markup: don't treat Django template tags as GitBook tags

[das-g]

Django template tags that aren't in code blocks are currently mis-interpreted as GitBook template tags, leading to wrong rendering, e.g. of

tutorial-extensions/en/homework_create_more_models/README.md

Lines 80 to 82 in b0c08b0

	## Make our comments visible
	Go to the `blog/templates/blog/post_detail.html` file and add the following lines before the `{% endblock %}` tag:

at https://tutorial-extensions.djangogirls.org/en/homework_create_more_models#make-our-comments-visible:

This change (wrapping those tags in {% raw %} ... {% endraw %}) should hopefully fix that, but I didn't try it locally, so I couldn't check how the result looks.

Thanks to @macmurdo for pointing out this problem on Gitter.

[magul]

I'm assuming that it will work, but really don't know how to test it locally (and if it will be pushed to new GitBook).

I recall discussion in DjangoGirls/djangogirls#537 about migration to new GitBook - it would be great if @amakarudze could share how to build these assets locally and how to ensure they were deployed successfully?

[das-g]

As there hasn't been any feedback, shall we just merge this and see how the result looks?

[das-g]

As there hasn't been any replies and the issue continued to confuse readers of the tutorial extensions, I've merged this now, hoping it fixes the problem properly. If it makes things worse, we can always revert.