Chore/class wrapper

[MarikaBBB]

This PR is a follow up to the issue #32 and ensure that govuk-main-wrapper remains intact and functional. I made sure that the govuk-main-wrapper--l , mixin are not in used and has been removed before taking over this issue.

I believe no father action is required.

[RobjS]

Hey @MarikaBBB, I think potentially there is some confusion here on the difference between a mixin and a standard CSS class.

A mixin is a set of styles defined in SASS that you can then re-use without having to re-write all the CSS every time: https://sass-lang.com/documentation/at-rules/mixin/.

It's the govuk-main-wrapper mixin that has been removed from the govuk-frontend. The .govuk-main-wrapper class is still supported, and expected to be part of the HTML template. As far as I can see, we're not using the mixin, so it may be that there isn't actually any work to address this issue. But I might be missing something!

[MarikaBBB]

Thank you @RobjS . In this case my PR is just to review the issue, and verify that the govuk-main-wrapper class is still supported and functional. In this case, I will delete the code I wrote and change the PR description.