Update readme

Not perfect, close enough.  cc: @erikap

Author: madnificent

README.md

@@ -36,7 +36,7 @@ curl localhost:8080/hello
 
 ### Dependencies
 
-If your service needs external libraries other than the ones already provided by the template (Flask, SPARQLWrapper and rdflib), you can specify those in a [`requirements.txt`](https://pip.pypa.io/en/stable/reference/requirements-file-format/)-file. The template will take care of installing them when you build your Docker image.
+If your service needs external libraries other than the ones already provided by the template (Flask, SPARQLWrapper and rdflib), you can specify those in a [`requirements.txt`](https://pip.pypa.io/en/stable/reference/requirements-file-format/)-file. The template will take care of installing them when you build your Docker image and when you boot the template in development mode for the first time.
 
 ### Development mode