Add a direntry to the Rottlog info manual.

diff --git a/doc/rottlog.texi b/doc/rottlog.texi
index 0ba8019..0f29916 100644
--- a/doc/rottlog.texi
+++ b/doc/rottlog.texi
@@ -18,6 +18,11 @@ Documentation License.''
 @end quotation
 @end copying
 
+@dircategory System administration
+@direntry
+* Rottlog: (rottlog).         The GNU log management utility.
+@end direntry
+
 @paragraphindent none
 
 @iftex
an='2'><a href='/'><img src='https://git.koszko.org/cgit-static/cgit.png' alt='cgit logo'/></a></td>
<td class='main'><a href='/'>index</a> : <a href='/guix/'>guix</a></td><td class='form'><form method='get'>
<input type='hidden' name='id' value='2ff90902c07ad377f94d94bd2b047e7170171a41'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=2ff90902c07ad377f94d94bd2b047e7170171a41'>refs</a><a class='active' href='/guix/log/gnu/packages/rrdtool.scm'>log</a><a href='/guix/tree/gnu/packages/rrdtool.scm?id=2ff90902c07ad377f94d94bd2b047e7170171a41'>tree</a><a href='/guix/commit/gnu/packages/rrdtool.scm?id=2ff90902c07ad377f94d94bd2b047e7170171a41'>commit</a><a href='/guix/diff/gnu/packages/rrdtool.scm?id=2ff90902c07ad377f94d94bd2b047e7170171a41'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/rrdtool.scm'>
<input type='hidden' name='id' value='2ff90902c07ad377f94d94bd2b047e7170171a41'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=2ff90902c07ad377f94d94bd2b047e7170171a41'>root</a>/<a href='/guix/log/gnu?id=2ff90902c07ad377f94d94bd2b047e7170171a41'>gnu</a>/<a href='/guix/log/gnu/packages?id=2ff90902c07ad377f94d94bd2b047e7170171a41'>packages</a>/<a href='/guix/log/gnu/packages/rrdtool.scm?id=2ff90902c07ad377f94d94bd2b047e7170171a41'>rrdtool.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/rrdtool.scm?id=2ff90902c07ad377f94d94bd2b047e7170171a41&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-05-03 12:36:07 +0200'>2023-05-03</span></td><td><a href='/guix/commit/gnu/packages/rrdtool.scm?id=0abde609f277eccca36a5ee3b58e972ca0c2afac'>gnu: rrdtool: Update to 1.8.0.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/rrdtool.scm (rrdtool): Update to 1.8.0.
[source]: Change URI making Github the primary distribution point;
[inputs]: Use new style;
[arguments]: Use gexps, remove PRE-CONFIGURE phase.

Signed-off-by: Nicolas Goaziou &lt;mail@nicolasgoaziou.fr&gt;
</span></span></td><td>Aleksandr Vityazev</td></tr>
<tr><td><span title='2022-01-20 13:11:37 -0500'>2022-01-20</span></td><td><a href='/guix/commit/gnu/packages/rrdtool.scm?id=f223535e1c2f052f671e44a6c546d0ebde3591b1'>gnu: rrdtool: Disallow references to tzdata-for-tests.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/rrdtool.scm (rrdtool)[arguments]: Add a #:disallowed-references
keyword.
</span></span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2022-01-20 13:11:37 -0500'>2022-01-20</span></td><td><a href='/guix/commit/gnu/packages/rrdtool.scm?id=af38141a1cba4a937de3d37d53a93f73d6ebfb67'>gnu: rrdtool: Use Python 3.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/rrdtool.scm (rrdtool)[inputs]: Replace PYTHON-2 with PYTHON.
</span></span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2021-12-13 17:48:25 +0100'>2021-12-13</span></td><td><a href='/guix/commit/gnu/packages/rrdtool.scm?id=8394619baceb118df92e355377fd543bb1aa501a'>gnu: Simplify package inputs.</a><span class='msg-avail'>...<span class='msg-tooltip'>This commit was obtained by running:

  ./pre-inst-env guix style

without any additional argument.
</span></span></td><td>Ludovic Courtès</td></tr>