Reword the recent deobfuscation changes

In most cases the word was changed to 'obfuscation' as it was about
obfuscation, not deobfuscation. In some cases like 1995/leo since the
file was (in 1995/leo) about a secret switch it was changed to
'secret.md' (and 'secret.html') but there were others like that as well.

One entry had the words 'spoiling the size rule' but this had been
changed to 'deobfuscating the size rule' which was obviously wrong.

In the latter YYYY/README.md files the judges had written after some
entries (brief summaries) '...

    ...We'll stop spouting spoilers now. Have fun exploring all the
    entries!

but that was changed to:

    ...We'll stop spouting deobfuscation information now. Have fun
    exploring all the entries!

which wasn't really about deobfuscation but just a brief summary of what
the entries did.

And in the most problematic case (at least for me :-), 2018/ferguson) I
had put a joke in:

    ... but it's the only Easter egg I won't spoil

but it was changed to 'won't deobfuscate' which not only is not what it
is but it spoilt the joke.

In some cases the word was changed back to 'SPOILER' (or similar) but in
most cases not. I believe it should be better now. There are some
caveats, however, as below.

Although make find_missing_links is okay I do not remember if this will
catch links that refer to '%%REPO_URL%%' or other pandoc tokens. This
means I might have to go back to some earlier years to verify links are
okay. That should not take that much time I hope.

It might also be that some wording can still be improved some but it is
hoped this will be discovered when checking links and looking over the
manifest (which obviously changed).

thanks-for-help.html

@@ -2183,8 +2183,9 @@ added.</p>
 <h3 id="winning-entry-source-code-leo.c-1">Winning entry source code: <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1995/leo/leo.c">leo.c</a></h3>
 </div>
 <p><a href="#cody">Cody</a> added the <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1995/leo/try.sh">try.sh</a> script.</p>
-<p>At our change in how to deal with deobfuscation, Cody also uudecoded the deobfuscation inforation provided
-by the author, putting it in <a href="1995/leo/deobfuscation.html">deobfuscation.html</a>.</p>
+<p>At our change in how to deal with spoilers, Cody also uudecoded the spoiler
+information about the secret switch, provided by the author, putting it in
+<a href="1995/leo/secret.html">secret.html</a>.</p>
 <div id="1995_makarios">
 <h2 id="winning-entry-1995makarios">Winning entry: <a href="1995/makarios/index.html">1995/makarios</a></h2>
 <h3 id="winning-entry-source-code-makarios.c">Winning entry source code: <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1995/makarios/makarios.c">makarios.c</a></h3>
@@ -4010,9 +4011,6 @@ to remove some text files so as to not cause problems with an invalid manifest.<
 <p>To silence the annoying misleading indentation warning and to prevent debug
 symbols from being built with <code>rake</code> Cody also updated the
 <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2014/endoh1/Rakefile">Rakefile</a> slightly.</p>
-<p><strong><em>Barely</em></strong> worth noting but done nonetheless, Cody renamed the <code>read_me.html</code>
-file to <a href="2014/endoh1/deobfuscation.html">deobfuscation.html</a> to be clearer in its purpose as
-it is a file with deobfuscation information.</p>
 <div id="2014_endoh2">
 <h2 id="winning-entry-2014endoh2">Winning entry: <a href="2014/endoh2/index.html">2014/endoh2</a></h2>
 <h3 id="winning-entry-source-code-prog.c-3">Winning entry source code: <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2014/endoh2//prog.c">prog.c</a></h3>
@@ -4536,7 +4534,9 @@ a friend, whether that’s real or imagined.</p>
 </div>
 <p><a href="#cody">Cody</a> copied the files from the <code>spoiler.zip</code> file (from his copy during
 the preview period) that was password protected with a password that was no
-longer known (but fortunately was already extracted).</p>
+longer known (but fortunately was already extracted). These files, originally
+put in <code>spoiler/</code> were moved to
+<a href="2020/endoh2/obfuscation/index.html">obfuscation/</a>.</p>
 <p>He also added the <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2020/endoh2/try.sh">try.sh</a> script.</p>
 <div id="2020_endoh3">
 <h2 id="winning-entry-2020endoh3">Winning entry: <a href="2020/endoh3/index.html">2020/endoh3</a></h2>