doc: Refactor manual index, make sections

doc/manual/index.rst

@@ -1,28 +1,58 @@
-ARTIQ documentation
-===================
+ARTIQ manual
+============
 
 .. toctree::
-    :caption: Contents
+    :caption: Overview  
     :maxdepth: 2
-
+    
     introduction
     release_notes
+
+.. toctree::
+    :caption: Setting up ARTIQ 
+    :maxdepth: 2
+
     installing
     developing
+    
+.. toctree::
+    :caption: Tutorials   
+    :maxdepth: 2
+
     rtio
     getting_started_core
     getting_started_mgmt
     using_drtio_subkernels
+
+.. toctree::
+    :caption: ARTIQ components  
+    :maxdepth: 2    
+
     environment
     compiler
     management_system
     drtio 
     core_device
+
+.. toctree::
+    :caption: Network devices  
+    :maxdepth: 2
+
+    developing_a_ndsp
+    list_of_ndsps
+    default_network_ports
+
+.. toctree::
+    :caption: References  
+    :maxdepth: 2
+
     main_frontend_reference
     core_language_reference
     core_drivers_reference 
     utilities
-    developing_a_ndsp
-    list_of_ndsps
-    default_network_ports
+
+.. toctree::
+    :caption: Addenda 
+    :maxdepth: 2
+    
     faq