Link to new documentation and details about sbt assembly (#113)

* Link to new documentation and details about sbt assembly

* Add example for assembly merge strategy

Author: gbecan

README.md

@@ -4,7 +4,26 @@ This repository contains examples of custom deserializers usable in Conduktor wi
 
 You can download the latest jar containing these deserializers [my_custom_deserializers_2.13-2.3.0.jar](https://github.com/conduktor/my_custom_deserializers/packages/1105212)
 
-To learn how to use the "custom deserializer" feature see [Conduktor documentation](https://docs.conduktor.io/features/consuming-data/custom-deserializers)
+To learn how to use the "custom deserializer" feature see [Conduktor documentation](https://docs.conduktor.io/platform/guides/custom-deserializers/)
+
+## How to build and package custom deserializers
+
+Console requires a single jar containing all dependencies (also known as a "fat" jar) to be able to use a custom deserializer.
+To build such a jar for the examples in this repository, you simply have to run:
+```sbt assembly```
+
+If you modify the examples to include new dependencies, please make sure that the [assembly merge strategy](./build.sbt) is properly configured to include all the necessary files for your dependencies to work. 
+
+For example, if you make add a Custom deserializer using protobuf to this repository, you should modify the existing assembly merge strategy as following:
+
+```scala
+assembly / assemblyMergeStrategy := {
+  case PathList("META-INF", "versions", "9", "module-info.class") => MergeStrategy.first
+  case PathList("com", "google", "type", xs @ _*) => MergeStrategy.first                  // New line to properly merge Google libraries
+  case x => (assembly / assemblyMergeStrategy).value(x)
+}
+```
+
 
 ## Simple example