Update the build instruction for new Vault

BUILD.md

@@ -19,26 +19,20 @@ When run, the server is accessible in [http://localhost:80](http://localhost:80)
 ### Install the web-vault
 Download the latest official release from the [releases page](https://github.com/bitwarden/web/releases) and extract it.
 
-Modify `web-vault/settings.Production.json` to look like this:
-```json
-{
-  "appSettings": {
-    "apiUri": "/api",
-    "identityUri": "/identity",
-    "iconsUri": "/icons",
-    "stripeKey": "",
-    "braintreeKey": ""
-  }
-}
-```
-
-Then, run the following from the `web-vault` directory:
+Apply the patch file from `docker/set-vault-baseurl.patch`:
 ```sh
-npm install
-npx gulp dist:selfHosted
+# In the Vault repository directory
+git apply /path/to/bitwarden_rs/docker/set-vault-baseurl.patch
 ```
 
-Finally copy the contents of the `web-vault/dist` folder into the `bitwarden_rs/web-vault` folder.
+Then, build the Vault:
+```sh
+npm run sub:init
+npm install
+npm run dist
+```
+
+Finally copy the contents of the `build` folder into the `bitwarden_rs/web-vault` folder.
 
 # Configuration
 The available configuration options are documented in the default `.env` file, and they can be modified by uncommenting the desired options in that file or by setting their respective environment variables. Look at the README file for the main configuration options available.