chore: improve docker image

Dockerfile

@@ -5,9 +5,8 @@ EXPOSE $PORT
 
 WORKDIR /app
 
-RUN npm install -g nodemon
-
-COPY package*.json .
+COPY package.json .
+COPY package-lock.json .
 
 RUN npm install
 
@@ -15,4 +14,4 @@ COPY src .
 COPY index.ts .
 COPY public .
 
-CMD [ "nodemon", "--transpile-only", "index.ts" ]
+CMD [ "npm", "run", "start" ]