Allow disabling text template generation

[aaronjensen]

The text template generation leaves quite a bit to be desired so we tend to write our own text templates manually.

For some reason, templates generated by smoothie are super slow with dialyzer.

It'd be great if we could disable text template generation so we could reduce the size of the template module and hopefully reduce the time it takes dialyzer to process the template module.

[jfrolich]

Thanks for the feedback! Will look into this.

[stephenmoloney]

just curious, what are the text templates for? I haven't had a need for them yet. I'd be in favour of making them optional.

[jfrolich]

For providing a plain text version of the email for clients that cannot handle HTML formatting.

[jfrolich]

Agree with making them optional 👍

[stephenmoloney]

I can add an option for this. Will try get to it eventually. Should be easy to implement.