This provides a checkbox when installing wsh that will prevent the
message from popping up in the future. It can also be disabled by adding
`"askbeforewshinstall": false` to the config file.
A couple small things:
- make the timer more robust in case of a timing issue where the timer
skips 0
- make the x button in the corner work
- style the title to stand out
The title will need more styling in the future, but this is still an
improvement.
