Add viewport meta tag to Storybook

[kvendrik]

Currently even when viewing the isolated component (http://localhost:6006/iframe.html?selectedKind=Playground&selectedStory=Playground) components can only be viewed on mobile in desktop size because of the absence of a viewport meta tag.

Potential fix here

[ry5n]

This prevents us from manually testing component changes in mobile browsers—pretty important. Just checked master; the potential fix linked to above is merged, but the issue is still there.

[kvendrik]

@ry5n 7d41ec0 was never merged as it was out-of-scope for the PR, it was removed in 39d74dd before the PR got merged. 🙂

[ry5n]

🙋‍♂️ If that changeset is all that’s needed I’m happy to open it as a new PR

[kvendrik]

@ry5n seems to be the case but wanted to address it separately at some point as I don't know if there are edge cases where it could potentially mess up the testing env. Feel free to open a PR 🙂

[kvendrik]

Note: the fix seems to only work when on http://localhost:6006/iframe.html?selectedKind=Playground&selectedStory=Playground and not within the StoryBook UI. cc @ry5n