feat: .env.example and vite config

added example
added comments in vite config for clarification

backend/.env.example

@@ -0,0 +1,7 @@
+POSTGRES_USER = # your postgres username
+POSTGRES_PASSWORD = # your postgres password
+
+POSTGRES_IP = # your postgres IP
+POSTGRES_PORT = # your postgres port
+
+JWT_SECRET = # ultra secret word

vite.config.js

@@ -4,7 +4,9 @@ import react from '@vitejs/plugin-react-swc';
 // https://vitejs.dev/config/
 export default defineConfig({
   server: {
+    // port for exposing frontend
     port: 3000,
+    // port for exposing APIs
     proxy: {
       '/api': 'http://localhost:3003',
       '/proxy': 'http://localhost:3003',