Create structure for tmp dir

[mbalex99]

The Electron app needs a place to store things

1. A tmp/user/${userId}/${rosId} dir for synced realms
2. A tmp/user/${userId}/settings to save things like last opened realm or schema etc...

Think of number 2 being more of a User Default

[kraenhansen]

@mbalex99. Do you have thoughts on what number 2 could be? A local Realm or perhaps a simple .json file or a directory of .jsons? It seems Electron has a good API to get the relevant file paths based on the OS: https://github.com/electron/electron/blob/master/docs/api/app.md#appgetpathname

[mbalex99]

Yeah I think number 2 can just be another realm. Either that or it can just be a localStorage json

[kraenhansen]

This line could be changed to have the realms stored in the "temp" directory: https://github.com/realm/realm-studio/blob/master/src/renderer.tsx#L7-L8