Sander/css scoping

[SanderElias]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/scullyio/scully/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Other... Please describe:

What is the current behavior?

Content rendered through the <scully-content> component could not be styled by using the css off the containing component.

What is the new behavior?

Putting CSS in the component that holds the <scully-content> will now properly style all content that is injected by scully

Does this PR introduce a breaking change?

• Yes
• No

Other information

[SanderElias]

When this is merged, we need to release the NPM modules at the same time.
Scully-component and the Scully content-render plugin are now using a slightly different way to pass information. both will not work with older versions.