Update photonics/index.html

photonics/index.html

@@ -78,10 +78,10 @@
     in <code><a href="https://gitlab.onelab.info/doc/models/-/wikis/Bloch-modes-in-periodic-waveguides"
     >models/BlochPeriodicWaveguides</a></code>.
   <li>A collection of non-Linear eigenvalue
-      problems<a href="#7"><sup>7-8</sup></a> (quadratic, polynomial and
-      rational) is avaiable in
-      <code><a href="https://gitlab.onelab.info/doc/models/-/tree/master/NonLinearEVP"
-      >models/NonLinearEVP</a></code>.
+    problems<a href="#7"><sup>7-8</sup></a> (quadratic, polynomial and
+    rational) is avaiable in
+    <code><a href="https://gitlab.onelab.info/doc/models/-/tree/master/NonLinearEVP"
+    >models/NonLinearEVP</a></code>.
 </ul>
 
 <h2>References</h2>