Add link to 0.5.x migration guide

[ci skip]

docs/appendices/0.5.0-migration-guide.md

@@ -1,5 +1,7 @@
 # 0.5.0 Migration Guide
+
 ## nginx-vhosts
+
 - The nginx-vhosts template language is now [sigil](https://github.com/gliderlabs/sigil)
   - No need to escape literal `$` characters (or other "bash-isms")
   - Template variables are represented as {{ .VARIABLE_NAME }}

docs/template.html

@@ -59,7 +59,7 @@
           <div class="list-group">
             <a href="#" class="list-group-item disabled">Getting Started</a>
             <a href="/dokku/installation/" class="list-group-item">Getting Started with Dokku</a>
-            <a href="/dokku/upgrading/" class="list-group-item">Upgrading</a>
+            <a href="/dokku/upgrading/" class="list-group-item">Upgrading Dokku</a>
             <a href="/dokku/troubleshooting/" class="list-group-item">Troubleshooting</a>
             <a href="/dokku/getting-started/where-to-get-help/" class="list-group-item">Getting Help</a>
 

docs/upgrading.md

@@ -6,6 +6,14 @@ This document covers upgrades for the 0.3.0 series and up. If upgrading from old
 
 ## Dokku
 
+### Migration Guides
+
+Migration guides contain information regarding the new features introduced in each version and the migration path between versions.
+
+- [0.5 Migration Guide](/dokku/appendices/0.5.0-migration-guide/)
+
+### General Information
+
 If dokku was installed via a debian package, you can upgrade dokku via the following command:
 
 ```shell