feat: switch from npm to yarn (#500)

* feat: switch from npm to yarn

* fix: build

* fix: replace yarn run with yarn

* fix: nodejs version install in Docker image

* fix: initialize mobx state

Co-authored-by: Karol Sójko <karolsojko@gmail.com>

README.md

@@ -88,9 +88,10 @@ This repo contains the core code used in the web app, as well as the Electron-ba
 
 **Instructions:**
 
+1. Ensure you have [Yarn](https://classic.yarnpkg.com) installed
 1. Clone the repo
-1. `npm run setup`
-1. `npm start`
+1. `yarn setup`
+1. `yarn start`
 
 Then open your browser to `http://localhost:3001`.