update: added the link to main website on the sidebar (#1216)

* update: added the link to main website on the sidebar

* update: changed from official website to View homepage

Co-authored-by: jakirkham <[email protected]>

Author: steph237

docs/index.rst

@@ -130,6 +130,7 @@ Contents
     contributing
     release
     license
+    View homepage <https://zarr.dev/>
 
 Indices and tables
 ------------------