improve display_via_github and display_as values

Fixed some inconsistent use of display_via_github and display_as values.

2019/yang/index.html

@@ -291,8 +291,8 @@ the same name, the character who is highly skilled in writing letters.</p>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/yang/prog.c">prog.c</a> - entry source</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/yang/Makefile">Makefile</a> - entry Makefile</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/yang/prog.orig.c">prog.orig.c</a> - original source</li>
-<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/yang/ioccc.txt">ioccc.txt</a> - sample input</li>
-<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/yang/sample_input.txt">sample_input.txt</a> - sample input</li>
+<li><a href="ioccc.txt">ioccc.txt</a> - sample input</li>
+<li><a href="sample_input.txt">sample_input.txt</a> - sample input</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/yang/try.sh">try.sh</a> - how to run</li>
 <li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/yang/violet.c">violet.c</a> - source formatter as ASCII Violet Evergarden</li>
 <li><a href="spoiler.html">spoiler.html</a> - SPOILER WARNING</li>