Make ^NOTE in markdown/html files bold

2015/yang/index.html

@@ -419,7 +419,7 @@ Location: <a href="../../location.html#US">US</a> - <em>United States of America
 this entry uses to tell the 5 languages/flavors apart. Can you find all four?</p>
 <p>The way the text is encoded in the output doesn’t cease to amaze. Can you tell
 why an array of 512 elements is needed?</p>
-<p>NOTE: the author calls the program <code>Fuuko</code> and so the source file referred to in
+<p><strong>NOTE</strong>: the author calls the program <code>Fuuko</code> and so the source file referred to in
 their remarks uses <code>fuuko.c</code>. The <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/yang/Makefile">Makefile</a> will compile everything
 so you need not worry about this.</p>
 <h2 id="authors-remarks">Author’s remarks:</h2>