Make ^NOTE in markdown/html files bold

2013/hou/index.html

@@ -446,7 +446,7 @@ really just a decompressor to generate the real source code of the
 program.</p>
 <p>This program will loop infinitely while progressively refining a
 <a href="https://en.wikipedia.org/wiki/Ray_tracing_(graphics)">raytraced</a> image.</p>
-<p>NOTE: the author refers to <code>a.c</code>, placed in a gzipped file <code>a.c.gz</code>. We do not
+<p><strong>NOTE</strong>: the author refers to <code>a.c</code>, placed in a gzipped file <code>a.c.gz</code>. We do not
 include it but it can be generated like:</p>
 <pre><code>    make a.c</code></pre>
 <p>There is no longer a need to do this as the Makefile takes care of it without