Update introduction-to-the-metacell-concept.html

fix path for image1. has to be also fixed at source

Author: mariiabilous

docs/introduction-to-the-metacell-concept.html

@@ -90,7 +90,7 @@ <h1>Introduction to the metacell concept<a class="anchor" aria-label="anchor" hr
 <p>Using metacells enables users to: (i) remove some of the noise while preserving and enhancing biological signal in sparse single-cell genomics data and,
 (ii) address computational challenges due to the large size of these data.</p>
 <div class="figure">
-<img src="images/figure1.png" alt=""><p class="caption">The metacell concept.</p>
+<img src="../images/figure1.png" alt=""><p class="caption">The metacell concept.</p>
 </div>
 <p>Several studies have been built upon the metacell concept. In this tutorial, we consider three tools providing standalone metacell construction frameworks and
 describe the different steps that should be followed to build metacells using these tools: