More details in guidelines

This includes updates from a recent change in txzchk and more details
about the tools and what they check (warnings and errors) and how to use
them individually.

This does need to be reviewed further, possibly being shorted or
referring to an FAQ, but it's a good start.

The rules had a typo fix as well.

next/rules.html

@@ -416,7 +416,7 @@ writing by <a href="../contact.html">contacting the judges</a>.</p>
 <h2 id="ioccc-rules-version">IOCCC Rules version</h2>
 </div>
 <p class="leftbar">
-These <a href="rules.html">IOCCC rules</a> are version <strong>28.6 2024-07-10</strong>.
+These <a href="rules.html">IOCCC rules</a> are version <strong>28.7 2024-07-11</strong>.
 </p>
 <p><strong>IMPORTANT</strong>: Be sure to read the <a href="guidelines.html">IOCCC guidelines</a>.</p>
 <div id="change_marks">
@@ -899,7 +899,7 @@ entry.
 <p class="leftbar">
 The <code>txzchk(1)</code> tool will verify these (and other things) for you and
 the <code>chkentry(1)</code> tool will do additional checks on the contents of the
-<code>.auth.json</code> and <code>.info.json</code> files including JSON validity. If these checks
+<code>.auth.json</code> and <code>.info.json</code> files (including JSON validity). If these checks
 fail it is an error and <code>mkiocccentry(1)</code> will fail. In this case it is very
 <strong>possibly</strong> a bug; please <a href="https://github.com/ioccc-src/mkiocccentry/issues/new?assignees=&amp;labels=bug&amp;projects=&amp;template=bug_report.yml&amp;title=%5BBug%5D+%3Ctitle%3E">report it as a bug at the mkiocccentry issues
 page</a>.
@@ -908,7 +908,8 @@ page</a>.
 The tarball filename <strong>MUST</strong> pass <code>fnamchk(1)</code>; the tool <code>txzchk(1)</code>
 will run <code>fnamchk(1)</code> as part of its algorithm. If you use <code>mkiocccentry(1)</code>
 there should be no problem but if you were to package things manually it is
-possible there could be a problem and this is a big risk.
+possible there could be a problem and this poses a big risk of violating <a href="#rule17">Rule
+17</a>.
 </p>
 <p class="leftbar">
 The <code>fnamchk(1)</code>, which <code>txzchk(1)</code> executes, will verify that the