When I created the weather app I didn't have GadgetBridge installed, so I tried to follow the protocol on the [espurino website](https://www.espruino.com/Gadgetbridge), but it wasn't very helpful and I made some mistakes. This commit should fix these mistakes to stop the weather app from crashing, and so it displays the correct values. I have also added a new settings option called "Units", where apps can see what units the user would prefer (metric/imperial).
Signed-off-by: Tait Berlette <54515877+taitberlette@users.noreply.github.com>