Problem processing non-ERB (Haml, Slim) layouts about mjml-rails

[jbwl]

For the time being the documentation should contain a hint that other template languages than ERB are currently broken.

[sighmon]

@biastoch2 @jbwl would your favoured solutions be to change if template.source =~ /<mjml>/ to if compiled_source =~ /<mjml>/ as you've done in your fork @biatoch2 ?

[sighmon]

@aleksandrs-ledovskis I haven't used Haml or Slim, so will take your recommendation for the best way forward.

3. sounds like a pretty decent way forward to me if it's similar to how Asset Pipeline compilation handles things.

But again, please use your best judgement. :-)

[jbwl]

I tried the fix from @biatoch2 and it works for me. I'd vote for it.