title: asdf: No version is set for command elixir
body: <p>I use asdf to install Erlang and then Elixir.</p>
  <pre><code>asdf install elixir 1.14.0-rc.1-otp-25
  </code></pre>
  <p>This results in:</p>
  <pre><code>asdf install elixir 1.14.0-rc.1-otp-25
  </code></pre>
  <p>And then ...</p>
  <pre><code>$ elixir
  No version is set for command elixir
  Consider adding one of the following versions in your config file at 
  elixir 1.14.0-rc.1-otp-25
  $ |
  </code></pre>
  <p>Which config file is this referring to?</p>