Update CORTX-MOTR-ARCHITECTURE.md
Fix the link to parity declustered design document.
# Object Layout #
+ Object is an array of blocks. Arbitrary scatter-gather IO with overwrite. Object has layout.
+ Default layout is parity de-clustered network raid: N+K+S striping.
- + More details about [parity declustering](doc/pdclust/index.rst)
+ + More details about [parity declustering](pdclust/index.rst)
+ Layout takes hardware topology into account: distribute units to support fault-tolerance.
![image](./Images/6_Object_Layout.png)
