Fix typo

Author: beutlich

Modelica/package.mo

@@ -2027,7 +2027,7 @@ design of sensors apply:
     <li>In a <a href=\"modelica://Modelica.Icons.RoundSensor\">round sensor</a> the text size shall be</li>
         <ul>
         <li>either <code>{{-30,-10},{30,-70}}</code> (<strong>Fig.&nbsp;6(a)</strong>)</li>
-        <li>or <code>{{-50,-12},{50,-48}}</code> (<strong>Fig.&nbsp;6(b)</strong>), depending on the better readibility</li>
+        <li>or <code>{{-50,-12},{50,-48}}</code> (<strong>Fig.&nbsp;6(b)</strong>), depending on the better readability</li>
         </ul>
         
     <li>In a <a href=\"modelica://Modelica.Icons.RectangularSensor\">rectangular sensor</a> the text size shall be