Fixes for recent commits

The Makefile.example file now has the ALT_OBJ and ALT_TARGET (with a
comment explaining how to use it) and the alt rule (which if the
variables are left empty it will do nothing with 'make alt' or 'make
everything').

The example Makefile now has the everything rule as well, for those who
have an alt target.

Fix links to next/try.sh, next/try.alt.sh and next/Makefile.example in
html files (guidelines/rules/FAQ) to not link to GitHub as they're
supposed to be downloaded.

faq.html

@@ -893,7 +893,7 @@ this is not clear!</li>
 <p>If your submission has more than one use, or if you have interesting ways to
 invoke your program, perhaps using other commonly installed tools (or tools
 included in your submission), it can be helpful to include a <code>try.sh</code> script.</p>
-<p>A <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/next/try.sh">template try.sh</a> can be used as a
+<p>A <a href="next/try.sh">template try.sh</a> can be used as a
 starting point, or you can look at some of the others in the website, to get
 some ideas.</p>
 <p>It is not detrimental to your chances of winning if you do not include one as
@@ -903,7 +903,7 @@ does not mean that a program that cannot be used with other programs is less
 interesting or less likely to win, but we do enjoy interesting and creative uses
 of submissions.</p>
 <p>If you have alternate code that you are including, then you can use the
-<a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/next/try.alt.sh">try.alt.sh template</a> instead.</p>
+<a href="next/try.alt.sh">try.alt.sh template</a> instead.</p>
 <p>We recommend that you include the use of these scripts in the <code>try</code> rule in the
 example Makefile that you modify for your submission. See the
 FAQ on “<a href="#makefile">submission Makefiles</a>.</p>