fix: Rewrite instead of redirect /downloads/releases

[darcywong00]

Fixes #442 reverting redirects to rewrites

Comparison to legacy /downloads/releaeses/web.config rules

                <rule name="releases-tier/download" stopProcessing="true">
                  <!-- note: the tier is currently ignored -->
                  <match url="^(alpha|beta|stable)/(.+)$" />
                  <action type="Rewrite" url="_version_downloads.php?tier={R:1}&amp;version={R:2}" />
                </rule>

                <rule name="releases-download" stopProcessing="true">
                  <match url="^(.+)$" />
                  <action type="Rewrite" url="_version_downloads.php?version={R:1}" />
                </rule>

                <rule name="index" stopProcessing="true">
                  <match url="^$" />
                  <action type="Redirect" url=".." />
                </rule>