docs(asdf): match README with 0.16 (#13026)

Co-authored-by: Carlo Sala <carlosalag@protonmail.com>

plugins/asdf/README.md

@@ -1,32 +1,39 @@
-## asdf
+# asdf
 
 Adds integration with [asdf](https://github.com/asdf-vm/asdf), the extendable version manager, with support for Ruby, Node.js, Elixir, Erlang and more.
 
-### Installation
+## Installation
 
-1. [Download asdf](https://asdf-vm.com/guide/getting-started.html#_2-download-asdf) by running the following:
+1. [Install](https://asdf-vm.com/guide/getting-started.html#_1-install-asdf) asdf and ensure that's it's discoverable on `$PATH`;
+2. Enable it by adding it to your `plugins` definition in `~/.zshrc`:
 
-  ```
-  git clone https://github.com/asdf-vm/asdf.git ~/.asdf
-  ```
+```sh
+plugins=(asdf)
+```
 
-2. [Enable asdf](https://asdf-vm.com/guide/getting-started.html#_3-install-asdf) by adding it to your `plugins` definition in `~/.zshrc`.
+## Usage
 
-  ```
-  plugins=(asdf)
-  ```
+Refer to the [asdf plugin documentation](https://asdf-vm.com/guide/getting-started.html#_4-install-a-plugin) for information on how to add a plugin and install the many runtime versions for it.
 
-### Usage
+Example for installing the nodejs plugin and the many runtimes for it:
 
-See the [asdf documentation](https://asdf-vm.com/guide/getting-started.html#_4-install-a-plugin) for information on how to use asdf:
+```sh
+# Add plugin to asdf
+asdf plugin add nodejs 
 
-```
-asdf plugin add nodejs https://github.com/asdf-vm/asdf-nodejs.git
+# Install the latest available nodejs runtime version
 asdf install nodejs latest
-asdf global nodejs latest
-asdf local nodejs latest
+
+# Install nodejs v16.5.0 runtime version
+asdf install nodejs 16.5.0
+
+# Set the latest version in .tools-version in the current working directory
+asdf set nodejs latest
+
+# Set a version globally that will apply to all directories under $HOME
+asdf set -u nodejs 16.5.0
 ```
 
-### Maintainer
+## Maintainer
 
 - [@RobLoach](https://github.com/RobLoach)