lecture 3: fix typo

closes #112

Author: opqdonut

part1.html

@@ -2880,7 +2880,7 @@ <h2 data-number="3.2" id="partial-application"><span
 <span id="cb180-6"><a href="#cb180-6" aria-hidden="true" tabindex="-1"></a>[<span class="fl">1.0</span>,<span class="fl">0.5</span>,<span class="fl">0.3333333333333333</span>,<span class="fl">0.25</span>,<span class="fl">0.2</span>]</span></code></pre></div>
 <h2 data-number="3.3" id="prefix-and-infix-notations"><span
 class="header-section-number">3.3</span> Prefix and Infix Notations</h2>
-<p>Normal Haskell operators are applied with <em>prefix notation</em>,
+<p>Normal Haskell functions are applied with <em>prefix notation</em>,
 which is just a fancy way to say that the function name comes before the
 arguments. In contrast, operators are applied with <em>infix
 notation</em> – the name of the function comes between the