Add RSS link to the repository index.
Index: hg/templates/index.tmpl
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<item>
<title>#desc|firstline|escape#</title>
<link>#url#?cmd=file;file=#file#;filenode=#filenode#</link>
<description><![CDATA[#desc|escape|addbreaks#]]></description>
<author>#author|obfuscate#</author>
<pubDate>#date|rfc822date#</pubDate>>
</item>