docs: b/14510382 ISO language code, add link

<h2 id="CreateDirs">Create Locale Directories and String Files</h2> 

<p>To add support for more languages, create additional <code>values</code> directories inside

<code>res/</code> that include a hyphen and the ISO country code at the end of the

<code>res/</code> that include a hyphen and the ISO language code at the end of the

directory name. For example, <code>values-es/</code> is the directory containing simple

resourcess for the Locales with the language code "es".  Android loads the appropriate resources

according to the locale settings of the device at run time.</p>

according to the locale settings of the device at run time. For more information, see

 <a href="{@docRoot}guide/topics/resources/providing-resources.html#AlternativeResources">Providing Alternative Resources</a>.</p>

<p>Once you’ve decided on the languages you will support, create the resource subdirectories and

string resource files. For example:</p>