Render specified element

[SilveryStar]

Add feature: use the element option to specify the element to generate an image (can be used with content)

[SilveryStar]

@frinyvonnick There was an error in my pull requests during Run yarn test.

FAIL src/index.spec.js (23.261 s)
  ● node-html-to-image › batch › should create two images
    ENOENT: no such file or directory, open './generated/image1.png'
  ● node-html-to-image › batch › should return two buffe

I think the reason lies in the test data, because the new option element cannot be empty in content (like output)

[frinyvonnick]

Hi @SilveryStar 👋

Thank you for opening this pull request 🙏 Sorry for the late response I was in holidays then started a new job so I didn't have a lot of time. I'll give it a look as soon as possible 👍

[frinyvonnick]

@SilveryStar a pull request that passes tests has been opened #87 but It lacks documentation and the one you did here looks really great. Maybe you can merge both work?

[frinyvonnick]

Done in #114

[frinyvonnick]

This was released in v3.2.0 🚀