Add feature to get text & background color from inline CSS : td&th

[kifni41]

This is:

• a bugfix
• a new feature

Checklist:

• Changes are covered by unit tests
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change
• Documentation is updated as necessary

What does it change?

Updated Pull Request from #178 , forgot to create new branch

I'm not sure if others need this feature, but this feature is quite handy for me and my team to directly generate excel file from html text, usually our client want specific coloring for the excel file and usually we already have the html for that.

This is limited for inline css inside and tag.

[PowerKiKi]

I think it would be best to extract your new code into a private method. Also docs/references/features-cross-reference.md should be updated accordingly.

[kifni41]

@PowerKiKi that's good idea, i'll update later..

[PowerKiKi]

I think we can return early here to avoid too many nested blocks:

if (!isset($attributeArray['style'])) {
    return;
}

[PowerKiKi]

Thanks for the contribution

[kifni41]

you're welcome, i hope it'll be useful for others and i can contribute more in the future...