Removed yarn references.

Author: mikecao

README.md

@@ -38,18 +38,12 @@ A detailed getting started guide can be found at [umami.is/docs](https://umami.i
 - A server with Node.js version 18.18 or newer
 - A database. Umami supports [MariaDB](https://www.mariadb.org/) (minimum v10.5), [MySQL](https://www.mysql.com/) (minimum v8.0) and [PostgreSQL](https://www.postgresql.org/) (minimum v12.14) databases.
 
-### Install Yarn
-
-```bash
-npm install -g yarn
-```
-
 ### Get the Source Code and Install Packages
 
 ```bash
 git clone https://github.com/umami-software/umami.git
 cd umami
-yarn install
+npm install
 ```
 
 ### Configure Umami
@@ -70,15 +64,15 @@ mysql://username:mypassword@localhost:3306/mydb
 ### Build the Application
 
 ```bash
-yarn build
+npm build
 ```
 
 *The build step will create tables in your database if you are installing for the first time. It will also create a login user with username **admin** and password **umami**.*
 
 ### Start the Application
 
 ```bash
-yarn start
+npm run start
 ```
 
 *By default, this will launch the application on `http://localhost:3000`. You will need to either [proxy](https://docs.nginx.com/nginx/admin-guide/web-server/reverse-proxy/) requests from your web server or change the [port](https://nextjs.org/docs/api-reference/cli#production) to serve the application directly.*
@@ -113,8 +107,8 @@ To get the latest features, simply do a pull, install any new dependencies, and
 
 ```bash
 git pull
-yarn install
-yarn build
+npm install
+npm run build
 ```
 
 To update the Docker image, simply pull the new images and rebuild: