Add readme for FibonacciFit

fibonaccifit/README.md

+# Setup
+
+The Docker image needs to be built with the following command:
+
+    docker build -t fibonaccifit -f Dockerfile .
+    
+Each time the `Project.toml` is changed due to modified dependencies,
+the `fibonaccifit` Docker image needs to be rebuilt using the command
+above.