experiment with moving from npm to yarn

mock-api/.gitignore

@@ -0,0 +1,7 @@
+.pnp.*
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/releases
+!.yarn/sdks
+!.yarn/versions

mock-api/.yarnrc.yml

@@ -0,0 +1,3 @@
+nodeLinker: pnp
+
+yarnPath: .yarn/releases/yarn-3.4.1.cjs

mock-api/README.md

@@ -2,4 +2,4 @@
 
 When developing and testing the web interface, it's handy not to bother with re-flashing an ESP32 each time. The idea is to mimic the ESP using a mock/stub server that responds to the REST (HTTP POST & GET) and WebSocket calls.
 
-To set it up it do run `npm install` in the `mock-api` folder, then from the `interface` folder run `npm run standalone`. This will start the mock API server on port 3080 using data from `mock-api/server.js` and the web server runs on port 3000.
+To set it up it do run `yarn install` in the `mock-api` folder, then from the `interface` folder run `yarn run standalone`. This will start the mock API server on port 3080 using data from `mock-api/server.js` and the web server runs on port 3000.

mock-api/package.json

@@ -1,7 +1,6 @@
 {
   "name": "api",
   "version": "1.0.0",
-  "private": "true",
   "description": "mock api for EMS-ESP",
   "main": "server.js",
   "scripts": {
@@ -17,5 +16,6 @@
     "express-sse": "^0.5.3",
     "nodemon": "^2.0.20",
     "ws": "^8.12.0"
-  }
+  },
+  "packageManager": "yarn@3.4.1"
 }