Fixed: Fix trunk documentation generation in BuidBot (OFBIZ-12896)

It's difficult because the rendering depends of the renderer tool

For instance I use the AsciiDoctor Eclipse plugin and it works with
the relative path from the current file (documentation_guidelines.adoc)
include::resource/source.java[]
but not with the "absolute" path (relative to OFBiz root dir)
include::docs/asciidoc/resource/source.java[]

I trust the later will be ok in BB;
let's see before changing also user-manual.adoc

docs/asciidoc/developer-manual.adoc

@@ -191,19 +191,19 @@ Continuing the example, the FindInvoices screen contains many details including
 two forms. One form is for entering invoice search fields and the other form
 displays search results.
 
-include::_include/OFBizDocumentationSystem.adoc[leveloffset=+2]
+include::docs/asciidoc/_include/OFBizDocumentationSystem.adoc[leveloffset=+2]
 
 == Web Framework
 
-include::../../framework/webapp/src/docs/asciidoc/webapp.adoc[leveloffset=+1]
+include::framework/webapp/src/docs/asciidoc/webapp.adoc[leveloffset=+1]
 
 === Control Servlet
 
 ==== Requests
 
 ==== Views
 
-include::../../framework/entity/src/docs/asciidoc/entity-engine.adoc[leveloffset=+1]
+include::framework/entity/src/docs/asciidoc/entity-engine.adoc[leveloffset=+1]
 
 === Entities
 
@@ -217,13 +217,13 @@ include::../../framework/entity/src/docs/asciidoc/entity-engine.adoc[leveloffset
 
 === XML Data
 
-include::../../framework/datafile/src/docs/asciidoc/datafiles.adoc[leveloffset=+2]
+include::framework/datafile/src/docs/asciidoc/datafiles.adoc[leveloffset=+2]
 
 === Entity engine configuration
 
 === Supported databases
 
-include::../../applications/datamodel/DATAMODEL_CHANGES.adoc[leveloffset=+2]
+include::applications/datamodel/DATAMODEL_CHANGES.adoc[leveloffset=+2]
 
 == Service Engine
 A description of the service engine can be found at the
@@ -253,7 +253,7 @@ https://cwiki.apache.org/confluence/display/OFBIZ/Service+Engine+Guide[OFBiz wik
 
 === Platform Specific Code
 
-include::../../themes/docs/themes.adoc[leveloffset=+2]
+include::themes/docs/themes.adoc[leveloffset=+2]
 
 == Core APIs
 
@@ -274,13 +274,13 @@ include::../../themes/docs/themes.adoc[leveloffset=+2]
 === Web tools
 The Webtools application is the UI-gateway to all the framework functions.
 
-include::../../framework/webtools/src/docs/asciidoc/_include/webtools-main.adoc[leveloffset=+3]
+include::framework/webtools/src/docs/asciidoc/_include/webtools-main.adoc[leveloffset=+3]
 
-include::../../framework/minilang/src/docs/asciidoc/minilang-to-groovy-manual.adoc[leveloffset=+1]
+include::framework/minilang/src/docs/asciidoc/minilang-to-groovy-manual.adoc[leveloffset=+1]
 
 == Testing
 
-include::../../framework/testtools/src/docs/asciidoc/unit-tests.adoc[leveloffset=+2]
+include::framework/testtools/src/docs/asciidoc/unit-tests.adoc[leveloffset=+2]
 
 === Integration Tests
 
@@ -291,12 +291,12 @@ https://cwiki.apache.org/confluence/display/OFBIZ/Framework+Configuration+Guide[
  (some points are not up to date).
 
 
-include::../../framework/base/src/docs/asciidoc/email.adoc[leveloffset=+2]
+include::framework/base/src/docs/asciidoc/email.adoc[leveloffset=+2]
 
-include::../../framework/security/src/docs/asciidoc/security.adoc[leveloffset=+1]
+include::framework/security/src/docs/asciidoc/security.adoc[leveloffset=+1]
 
 == Appendices
 
 // Developers Plugins
 
-include::../../plugins/docs/asciidoc/plugins-developer-manual.adoc[leveloffset=+1]
+include::plugins/docs/asciidoc/plugins-developer-manual.adoc[leveloffset=+1]

docs/asciidoc/documentation_guidelines.adoc

@@ -554,12 +554,12 @@ The following example imports a file formatted as Java source code.
 
   [source,java]
   ----
-  include::resource/source.java[]
+  include::docs/asciidoc/resource/source.java[]
   ----
 
 [source,java]
 ----
-include::resource/source.java[]
+include::docs/asciidoc/resource/source.java[]
 ----
 
 === Using leveloffset
@@ -583,12 +583,12 @@ This text will not be included!
 
 and include the file with the tagname in the brackets like this:
 
- include::resource/article.adoc[tags=tagname]
+ include::docs/asciidoc/resource/article.adoc[tags=tagname]
 
 The result would be
 
 ----
-include::resource/article.adoc[tags=tagname]
+include::docs/asciidoc/resource/article.adoc[tags=tagname]
 ----
 
 === Importing images