Pre-formatted block (blockquote) in msgfmt

This has existed for a while; must have forgotten to commit

msgfmt

@@ -98,6 +98,9 @@ awk -vid="$id" -vurl_root="${url_root%/}" -vcref_errlog="$cref_errlog" '
     # paragraph, unless that paragraph is also indented)
     s#\n\n  \+\(\([^\n]\+\n\(\n  \+\)\?\)\+\)#<blockquote>\1</blockquote>#g
 
+    # pre-formatted block. markdown-style
+    s#\n\n  \+\(\([^\n]\+\n\(\n  \+\)\?\)\+\)#<blockquote>\1</blockquote>#g
+
     # unfortunately, non-greedy matches make it difficult to exclude punctuation
     # at the end of a link, so we will handle it in a separate expression
     s#[fh]ttps\?://[^]\n )]\+#<a href="&">&</a>#g;