[WIP] Overhaul the documentation site (#1030)

Overhaul the whole documentation site

docs/posts/gallery.md

@@ -0,0 +1,34 @@
+---
+title: Gallery
+subtitle: Features & examples
+layout: default
+---
+
+# Features
+
+### Cross-filter cells and color by metadata  
+<img src="../images/crossfilter.gif" width="600"/>
+
+### Compare groups of cells with differential expression  
+<img src="../images/diffexp.gif" width="600"/>
+
+### See how metadata and gene expression break down across categories  
+<img src="../images/category-breakdown.gif" width="600"/>
+
+### Find cells where a gene is expressed  
+<img src="../images/gene-expression.gif" width="600"/>
+
+### Compare expression of multiple genes  
+<img src="../images/compare-genes.gif" width="600"/>
+
+# Interactive demos  
+
+Several groups have independently [deployed](hosted) various versions of cellxgene to the web.
+Check out the cool data that our users are using cellxgene to explore!
+
+### [Kidney cell atlas](https://www.kidneycellatlas.org/)  
+### [Tabula muris senis](https://tabula-muris-senis.ds.czbiohub.org/)  
+### [Hemocytes](https://hemocytes.cellgeni.sanger.ac.uk/)
+### [Melanoma](https://melanoma.cellgeni.sanger.ac.uk/)
+
+_Want us to link to your dataset here? [Just send us a note!](contact)_