* Add a Jest snapshot of AppPermission
* Move the test inside 'for a pinned widget' category
* Make only spinner message bold
* Set font size specified with "mx_AppPermission_smallText" by default
- Add "mx_AppPermission_largeText" for elements whose size has not been specified with mx_AppPermission_smallText
- Create _AppWarning.pcss for AppWarning
* Make AppPermission panel scrollable, keeping the content at the center
* Run prettier
* Use Heading component
* Use Icon component
* Fix the test
These icons are based on Feather as the original source, but they have various
tweaks applied, such as stroke width, color, etc. Hopefully the tweaked name
makes this more obvious in the future.
