docs: Fix missing v1beta1, v1alpha3 API versions (#3202)

PR #1345 assumed there would be two versions of the API for the "API
Specification" doc page. Now we have 4 versions, and 2 are left out
(v1beta1 and v1alpha3). This is a quick fix, but this will break every
API version release. We should pursue a more sustainable solution.

Author: gcs278

hack/api-docs/pkg.tpl

@@ -41,12 +41,16 @@ Resource Types:
 
 <p>Packages:</p>
 <ul>
-    {{ template "link" index .packages 1 }}
     {{ template "link" index .packages 0 }}
+    {{ template "link" index .packages 3 }}
+    {{ template "link" index .packages 2 }}
+    {{ template "link" index .packages 1 }}
 </ul>
 
-{{ template "package" index .packages 1 }}
 {{ template "package" index .packages 0 }}
+{{ template "package" index .packages 3 }}
+{{ template "package" index .packages 2 }}
+{{ template "package" index .packages 1 }}
 
 <p><em>
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