[generator.doc] Add top-level tagged region to generated adoc

- Allows the generated asciidoctor content to be included as a whole,
excluding the document header

Change-Id: I0f5c769cfab759d2d6126055e0bf4a7340262ee4

plugins/org.eclipse.etrice.generator.doc/src/org/eclipse/etrice/generator/doc/gen/AsciiDocGen.xtend

@@ -57,11 +57,12 @@ class AsciiDocGen {
 	
 	def generateSingleDoc(Iterable<RoomPackage> packages, boolean includeImages) '''
 		= Model Documentation
-		generated by eTrice
-		{docdatetime}
 		:toc: left
 		:toclevels: 2
 		:table-caption!:
+		tagStart("all")
+		generated by eTrice
+		{docdatetime}
 		IF !packages.empty
 			
 			.Room Packages
@@ -97,6 +98,7 @@ class AsciiDocGen {
 				ac.generateActorDoc(includeImages)
 			ENDFOR
 		ENDFOR
+		tagEnd("all")
 	'''
 	
 	def private generatePackageDoc(RoomPackage pkg) {
@@ -494,7 +496,11 @@ class AsciiDocGen {
 	def private static tagStart(RoomClass rc) '''// tag::rc.FQN[]'''
 	
 	def private static tagEnd(RoomClass rc) '''// end::rc.FQN[]'''
+
+	def private static tagStart(String name) '''// tag::.name[]'''
 	
+	def private static tagEnd(String name) '''// end::.name[]'''
+
 	def private static String fill(char c, int length) {
 		val builder = new StringBuilder(length)
 		for(var i = 0; i < length; i++) {