Updated readme installation section

Author: maxfrei

README.md

@@ -36,6 +36,13 @@ $ packer init examples/basic_example.pkr.hcl
 Installed plugin github.com/upcloudltd/upcloud v1.0.0 in "/Users/johndoe/.packer.d/plugins/github.com/upcloudltd/upcloud/packer-plugin-upcloud_v1.0.0_x5.0_darwin_amd64"
 ```
 
+After successful plugin installation, you can run the build command:
+```sh
+$ packer build examples/basic_example.pkr.hcl
+
+...
+```
+
 From Packer version 1.7.0, template HCL2 becomes officially the preferred way to write Packer configuration. While the `json` format is still supported, but certain new features, such as `packer init` works only in newer HCL2 format.
 If you are using `json` config templates, please consider upgrading them using the packer built-in command:
 
@@ -45,6 +52,8 @@ Successfully created example.json.pkr.hcl
 ```
 
 
+
+
 ### Pre-built binaries
 
 You can download the pre-built binaries of the plugin from the [GitHub releases page](https://github.com/UpCloudLtd/packer-plugin-upcloud/releases). Just download the archive for your operating system and architecture, unpack it, and place the binary in the appropriate location, e.g. on Linux `~/.packer.d/plugins`. Make sure the file is executable, then install [Packer](https://www.packer.io/).