Add formating to code includes

Signed-off-by: Stefan Cyliax <stefan.cyliax@asam.net>

Author: Stefan Cyliax

doc/misc/example.adoc

@@ -3,7 +3,7 @@
 Then following example shows the content of a `modelDescription.xml` file that satisfies the requirements of OSMP.
 The example describes a sensor model FMU with one input, one output, and no additional features:
 
-[source]
+[source,xml]
 ----
 <?xml version="1.0" encoding="UTF-8"?>
 <fmiModelDescription

doc/spec/basic_conventions.adoc

@@ -5,7 +5,7 @@ Unless otherwise noted, all specifications in the FMI 2.0 standard apply as-is.
 
 The following annotation shall be placed into the `<VendorAnnotations>` element of the `modelDescription.xml` to mark the FMU as being conformant to this version of the specification:
 
-[source]
+[source,xml]
 ----
 <Tool name="net.pmsf.osmp" xmlns:osmp="http://xsd.pmsf.net/OSISensorModelPackaging"><osmp:osmp version="1.1.1" osi-version="x.y.z"/></Tool>
 ----

doc/spec/binary_variables.adoc

@@ -33,7 +33,7 @@ Models FMUs shall handle this case safely.
 
 The three actual variables shall contain an annotation of the following form in the `<Annotations>` child element of their `<ScalarVariable>` element of the `modelDescription.xml`:
 
-[source]
+[source,xml]
 ----
 <Tool name="net.pmsf.osmp" xmlns:osmp="http://xsd.pmsf.net/OSISensorModelPackaging"><osmp:osmp-binary-variable name="<prefix>" role="<role>" mime-type="<mime-type>"/></Tool>
 ----
@@ -48,7 +48,7 @@ It is an error if the MIME types specified in the annotations for one notional b
 
 In the case of OSI-specified data, the MIME type shall have the following form to indicate that the binary content is conformant to the given OSI version and contains a message of the given type:
 
-[source]
+[source,xml]
 ----
 application/x-open-simulation-interface; type=<type>; version=x.y.z
 ----