Add shapes and footprints sections.

WIP for #5.

main/clients.bs

@@ -4,23 +4,38 @@ Clients and Apps {#clients}
 Issue: Write introduction to the Clients and Apps section.
 
 
-## Cross-Origin Resource Sharing ## {#cors}
+## Implementation Guidance ## {#client-guidance}
+<em>This section is non-normative.</em>
 
-Issue: Write Cross-Origin Resource Sharing section.
+Issue: Write Implementation Guidance section.
 
-A Solid data pod MUST conform to the CORS specification [[!FETCH]].
 
+## Data Shapes and Footprints ## {#shapes-footprints}
 
-## Implementation Guidance ## {#client-guidance}
+Issue: Write introduction to Data Shapes and Footprints section.
+
+
+### Data Shapes ### {#shapes}
+Issue: Write Data Shapes section.
 
-Issue: Write Implementation Guidance section.
+
+### Footprints ### {#footprints}
+Issue: Write Footprints section.
 
 
 ## Data Shape Guidance ## {#shape-guidance}
+<em>This section is non-normative.</em>
 
 Issue: Write Data Shape Guidance section.
 
 
+## Cross-Origin Resource Sharing ## {#cors}
+
+Issue: Write Cross-Origin Resource Sharing section.
+
+A Solid data pod MUST conform to the CORS specification [[!FETCH]].
+
+
 ## Update Notifications ## {#notifications}
 
 Issue: Write Update Notification section.