Implemented enhancement files emmpty + invalid path

[Bullfrog666]

The enhancement .adoc files in Target/structurizr/enhancement seems to be empty, is it normal and what is these files purpous.
+
.adoc files in src/docs/asciidoc/ include enhancers content with the line :
include::{enhancements-dir}/_10-deployment.adoc[leveloffset=+1]

But "{enhancements-dir}" seems not found (even if defined in the pom.xml) witch leads us to this error when rendering the .adoc file :
Unresolved directive in 10-deployment.adoc - include::{enhancements-dir}/_10-deployment.adoc[leveloffset=+1]

[Riduidel]

It is not found in IDE because we don't set an enhancements-dir default value in fil header.
This can be fixed by adding the following line as file header

:enhancements-dir: ${A_PATH_TO_DETERMINE}