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
'cgit'><table id='header'>
<tr>
<td class='logo' rowspan='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='162048be3b838e221e5256b0f670ac6f884f607a'/><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=162048be3b838e221e5256b0f670ac6f884f607a'>refs</a><a class='active' href='/guix/log/gnu/packages/patches/mrrescue-support-love-11.patch'>log</a><a href='/guix/tree/gnu/packages/patches/mrrescue-support-love-11.patch?id=162048be3b838e221e5256b0f670ac6f884f607a'>tree</a><a href='/guix/commit/gnu/packages/patches/mrrescue-support-love-11.patch?id=162048be3b838e221e5256b0f670ac6f884f607a'>commit</a><a href='/guix/diff/gnu/packages/patches/mrrescue-support-love-11.patch?id=162048be3b838e221e5256b0f670ac6f884f607a'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/patches/mrrescue-support-love-11.patch'>
<input type='hidden' name='id' value='162048be3b838e221e5256b0f670ac6f884f607a'/><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=162048be3b838e221e5256b0f670ac6f884f607a'>root</a>/<a href='/guix/log/gnu?id=162048be3b838e221e5256b0f670ac6f884f607a'>gnu</a>/<a href='/guix/log/gnu/packages?id=162048be3b838e221e5256b0f670ac6f884f607a'>packages</a>/<a href='/guix/log/gnu/packages/patches?id=162048be3b838e221e5256b0f670ac6f884f607a'>patches</a>/<a href='/guix/log/gnu/packages/patches/mrrescue-support-love-11.patch?id=162048be3b838e221e5256b0f670ac6f884f607a'>mrrescue-support-love-11.patch</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/patches/mrrescue-support-love-11.patch?id=162048be3b838e221e5256b0f670ac6f884f607a&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-06-19 22:20:15 +0200'>2018-06-19</span></td><td><a href='/guix/commit/gnu/packages/patches/mrrescue-support-love-11.patch?id=8893218a7d9c750e657cde17e3a670621ec3ea2e'>gnu: mrrescue: Work on Löve 11.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/games.scm (mrrescue)[arguments]: Extract &amp; patch the game
data, and point ‘love’ to this modified copy.  Minor cosmetic tweaks.
[native-inputs]: Add unzip, patch, and the love-11.patch which is...
* gnu/packages/patches/mrrescue-support-love-11.patch: ...a new file.
* gnu/local.mk (dist_patch_DATA): Add it.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>