add alternative demodataLink to website as well

docs/index.html

@@ -71,7 +71,7 @@ <h3>
 <h3>
 <a id="hmri-example-data-and-mri-protocol" class="anchor" href="#hmri-example-data-and-mri-protocol" aria-hidden="true"><span aria-hidden="true" class="octicon octicon-link"></span></a>Sample Dataset and MRI Acquisition Protocols</h3>
 <p>A sample dataset is provided as reference and material for exploring the possibilities and functionalities of the hMRI-toolbox.
-It is publicly available for download <a href="https://owncloud.gwdg.de/index.php/s/znxsMrPUB2TJsLz">here</a> (<a href="#Callaghan.2019">Callaghan et al., 2019</a>). 
+It is publicly available for download <a href="https://owncloud.gwdg.de/index.php/s/znxsMrPUB2TJsLz">here</a> but please use this <a href="https://mega.nz/folder/OnxDALZa#bFe0xKJTuuUeGXrYnlX8dA">altervative link</a> if the link is broken (<a href="#Callaghan.2019">Callaghan et al., 2019</a>). 
 Several example MRI protocols (standard MPM protocol using customised Siemens sequences, as well MPM protocol implemented using Siemens and Philips product sequences) 
 as well as a setup (for Siemens 3T MRI) and usage tutorial are available at the same URL. 
 Please be aware that we provide these protocols and information without any warranty.