Update motr-developer-guide.md
Added link to architectural reading list.
@@ -12,6 +12,7 @@ and [Quick Start Guide](/doc/Quick-Start-Guide.rst). For debugging, ADDB can be
very useful and is described in these [two](ADDB.rst) [documents](addb2-primer).
Cortx Motr provides object based operations and index (a.k.a key/value) based operations.
+For architectural documents, please refer to our [reading list](reading-list.md).
## A simple Cortx Motr application (object)
