Merge branch 'pc-fill-index' into 'master'

Add links to the main readme to point to design decisions

So they are visible from the front README of the project

See merge request !4

README.md

@@ -4,6 +4,11 @@
 ## Where and how to look for data
+### Design decisions
+
+* [Storage design](design/storage.md)
+* [Network design](design/networking.md)
+
 ### General System Health
 #### Blackbox Monitoring

design/README.md

 # GitLab Infastructure Design
-[Storage](design/storage.md)
-[Networking](design/networking.md)
+* [Storage](design/storage.md)
+* [Networking](design/networking.md)