Support output of ES5 compatible code

[ranyitz]

Feature Request

Support ES5 compatible output.

Why?

Reduce the build time when trying to run carmi code in the browser (to support old browsers)

Context

As part of our work on Thunderbolt we need to be able to run carmi code in the browser. Some of those browser (Like IE11) are quite old and requires transpilation for ES5.

Our current solution is to run babel on the output of carmi, this task takes a lot of time and raise the build time significantly.

Optional solution

Transpile the templates to ES5 as part of carmi's build and support ES5 mode when those templates will be used instead of the regular ones being used today.