This changes the layout of "organization settings" for
non-administrators such that they can view "Default streams" ("Actions"
and the form to add new default stream is not visible).
This restructures the styling for the Zulip settings and
administration pages to minimize use of Bootstrap and use a consistent
styling library for similar elements.
While it is basically a wash in terms of the page's visuals, it will
make our life a lot easier for future work on improving the settings
pages section of the site.
digi0ps
Abhijeet Kaur
adnrs96
Brock Whittaker
Vishnu Ks