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
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<div class='path'>path: <a href='/guix/log/?id=ccce23bd81b3386bdccddb8c65bd1718da13497f'>root</a>/<a href='/guix/log/tests?id=ccce23bd81b3386bdccddb8c65bd1718da13497f'>tests</a>/<a href='/guix/log/tests/utils.scm?id=ccce23bd81b3386bdccddb8c65bd1718da13497f'>utils.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/tests/utils.scm?id=ccce23bd81b3386bdccddb8c65bd1718da13497f&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-12-11 11:53:54 +0200'>2023-12-11</span></td><td><a href='/guix/commit/tests/utils.scm?id=520e3d267ecc3964af301ab9341462e905f234c6'>guix: Add target-avr?.</a><span class='msg-avail'>...</span></td><td>Jean-Pierre De Jesus DIAZ</td></tr>
<tr><td><span title='2021-07-14 15:38:03 +0200'>2021-07-14</span></td><td><a href='/guix/commit/tests/utils.scm?id=f54852be22c29a0d5b174d15ef6189c57cab2017'>utils: Define a target-x86-32? and target-x86-64? predicate.</a><span class='msg-avail'>...</span></td><td>Maxime Devos</td></tr>
<tr><td><span title='2021-07-14 15:38:03 +0200'>2021-07-14</span></td><td><a href='/guix/commit/tests/utils.scm?id=ef71965c162ff19c7b4b85889b0330d7c428dda5'>utils: Define 'target-linux?' predicate.</a><span class='msg-avail'>...</span></td><td>Maxime Devos</td></tr>
<tr><td><span title='2021-02-03 12:41:28 +0100'>2021-02-03</span></td><td><a href='/guix/commit/tests/utils.scm?id=9505b54a4f9f0265c9d8be53763f0c59d6f62a44'>utils: Add string distance.</a><span class='msg-avail'>...</span></td><td>zimoun</td></tr>
<tr><td><span title='2021-02-01 17:32:34 +0100'>2021-02-01</span></td><td><a href='/guix/commit/tests/utils.scm?id=579506e272cf68649ec68ad8a976a17426ea630c'>utils: Add 'version-unique-prefix'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-01-13 22:24:19 +0100'>2021-01-13</span></td><td><a href='/guix/commit/tests/utils.scm?id=db0cecdf6b2f2b8f9c5a3cebe8fc60e79a692be0'>utils: Support zstd compression via Guile-zstd.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-01-13 22:24:19 +0100'>2021-01-13</span></td><td><a href='/guix/commit/tests/utils.scm?id=0d046587107a56467cf2027799ac79ce8c203ce0'>utils: Remove 'compressed-output-port'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>