improve display_via_github and display_as values

Fixed some inconsistent use of display_via_github and display_as values.

2019/diels-grabsch1/index.html

@@ -201,9 +201,9 @@ goes.</p>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/diels-grabsch1/prog.c">prog.c</a> - entry source</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/diels-grabsch1/Makefile">Makefile</a> - entry Makefile</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/diels-grabsch1/prog.orig.c">prog.orig.c</a> - original source</li>
-<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/diels-grabsch1/guidelines.txt">guidelines.txt</a> - input data from 2018 IOCCC guidelines</li>
+<li><a href="guidelines.txt">guidelines.txt</a> - input data from 2018 IOCCC guidelines</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/diels-grabsch1/try.sh">try.sh</a> - how to run</li>
-<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/diels-grabsch1/Shakespeare.txt">Shakespeare.txt</a> - Coriolanus by Shakespeare</li>
+<li><a href="Shakespeare.txt">Shakespeare.txt</a> - Coriolanus by Shakespeare</li>
 </ul>
 <h2 id="secondary-files">Secondary files</h2>
 <ul>