Simmilar to include_str! from the stdlib but instead of including arbitrary files as &str
it includes sytactically valid javascript from files as &JSStr. If the file contains invalid
Javascript you will get a compiletime error.
Wrapper around str that ensures it contains syntactically valid Javascript.
This is the borrowed version of JSString so &JSStr is to JSString what &str is to String
Derives the JSTemplate trait for a struct with named fields.
This is simmilar to plain include_js! with the difference that
the Javascript is not yet fully filled in, so a template engine (in this case Handlebars)
to fill in the values at runtime.