Add vfox instructions in installation.md (#427)

Co-authored-by: Jo Franchetti <[email protected]>

runtime/manual/getting_started/installation.md

@@ -53,6 +53,18 @@ asdf global deno latest
 asdf local deno latest
 ```
 
+Using [vfox](https://vfox.lhan.me/):
+
+```shell
+vfox add deno
+
+# Download and install the latest version of Deno
+vfox install deno@latest
+
+# To set the version of Deno globally
+vfox use --global deno
+```
+
 </TabItem>
   <TabItem  value="windows" label="Windows">
 
@@ -80,6 +92,18 @@ Using [Winget](https://github.com/microsoft/winget-cli):
 winget install deno
 ```
 
+Using [vfox](https://vfox.lhan.me/):
+
+```shell
+vfox add deno
+
+# Download and install the latest version of Deno
+vfox install deno@latest
+
+# To set the version of Deno globally
+vfox use --global deno
+```
+
 </TabItem>
   <TabItem value="linux" label="Linux">
 
@@ -110,6 +134,18 @@ asdf global deno latest
 asdf local deno latest
 ```
 
+Using [vfox](https://vfox.lhan.me/):
+
+```shell
+vfox add deno
+
+# Download and install the latest version of Deno
+vfox install deno@latest
+
+# To set the version of Deno globally
+vfox use --global deno
+```
+
 </TabItem>
 </Tabs>