[Doc] Show how to install the phar by direct download (#5274)

docs/running_psalm/installation.md

@@ -35,8 +35,19 @@ Read more about plugins in [Using Plugins chapter](plugins/using_plugins.md).
 
 ## Using the Phar
 
-Sometimes your project can conflict with one or more of Psalm’s dependencies.
+Sometimes your project can conflict with one or more of Psalm’s dependencies. In
+that case you may find the Phar (a self-contained PHP executable) useful.
 
-In that case you may find the Phar (a self-contained PHP executable) useful.
+The Phar can be downloaded from Github:
 
-Run `composer require --dev psalm/phar` to install it.
+```bash
+wget https://github.com/vimeo/psalm/releases/latest/download/psalm.phar
+chmod +x psalm.phar
+./psalm.phar --version
+```
+
+Alternatively, you can use Composer to install the Phar:
+
+```bash
+composer require --dev psalm/phar
+```