fix(tailwind): add prefix to production class names

[affanshahid]

Component / Package Name: jsx-email (Tailwind)

This PR contains:

• [x] bugfix
• [ ] feature
• [ ] refactor
• [ ] documentation
• [ ] other

Are tests included?

• [x] yes (bugfixes and features will not be merged without tests)
• [ ] no

Breaking Changes?

• [ ] yes (breaking changes will not be merged unless absolutely necessary)
• [x] no

If yes, please include "BREAKING CHANGES:" in the first commit message body, followed by a description of what is breaking.

List any relevant issue numbers: resolves #110

Description

This PR adds a prefix to the class names generated by the class compiler transformer. This is to ensure that the class names generated, which may begin with a number, do not need to be escaped in the generated CSS, thus increasing compatibility with gmail clients

[lordelogos]

Thanks for this PR.

This is ready to go @shellscape