feature: add support for Eta template engine

[exoup]

I would like to add consolidate support for the Eta template engine.
I included an example of using custom options alongside consolidate, although it does work without specifying custom options.

Checklist

• I have ensured my pull request is not behind the main or master branch of the original repository.
• I have rebased all commits where necessary so that reviewing this pull request can be done without having to merge it first.
• I have written a commit message that passes commitlint linting.
• I have ensured that my code changes pass linting tests.
• I have ensured that my code changes pass unit tests.
• I have described my pull request and the reasons for code changes along with context if necessary.

[titanism]

hi there @exoup it looks like you forgot to add it to the README.md - please do so in another PR - see https://github.com/ladjs/consolidate#engines

v1.0.3 released to npm for both @ladjs/consolidate and conslidate

https://github.com/ladjs/consolidate/releases/tag/v1.0.3

thanks for your contribution @exoup

[floriannari]

email-templates issue with Eta template engine forwardemail/email-templates#458
(relative vs absolute path)