Adds the ability to add offset to background position

[albertski]

Ran into some issues with the background image. I would see a black area above the image.

I used the same formula found here and it seems to work better:

var yPos = -($window.scrollTop() / $bgobj.data('speed'));

Not sure if it was just me but that worked a lot better.

Also, needed the ability to add a little offset so the image displays in the position I would like it to show. I added an offset field that lets you control it.

[thejimbirch]

In general, when Drupal exports yaml files, I believe that the children of items are in alphabetical order.
Their position in Drupal can be ordered with the weight option.

In this case, dependencies > config and content > field_name should be re-ordered.

[albertski]

Good point. I made those fixes.

[thejimbirch]

Excellent! Chrissy and I will review in the morning. She handled the Javascript for this module.

[christine-harder]

The changes in xeno-hero.js look great. It is a lot cleaner.

[thejimbirch]

@albertski I made some changes to the template. Please review. If you approve, I will ask @christine-harder to merge the PR.

[albertski]

@thejimbirch Your changes look good and I tested and they worked.

Still not sure if you are required to set a default value like you do in php. I'm thinking you don't have to in Twig but jut incase created a question on Drupal Answers.

[thejimbirch]

We got good feedback on Drupal Answers that our solution is valid.

@christine-harder Let me know when you have availability and we can complete this Pull Request.

[christine-harder]

Pull request is merged 👍