fix minor typo on the home page

templates/index.html

@@ -32,7 +32,7 @@
 / \
 <img title="GNU Social" src="/static/gnu_social_logo.svg">   <img title="Pixelfed" src="/oauth_dropins_static/pixelfed_2x.png">
 </pre>
-<p class="big">Your web site will be its own fediverse account, including its posts. Its username and instance will be your domain. This takes a bit of technical known-how.</p>
+<p class="big">Your web site will be its own fediverse account, including its posts. Its username and instance will be your domain. This takes a bit of technical know-how.</p>
 </a>
 </div>
 </div>