Add cross-references to Eclipse4_Commands.md in FAQ and services documentation

Co-authored-by: laeubi <[email protected]>

Author: Copilot

docs/Eclipse4_RCP_EAS_List_of_All_Provided_Services.md

@@ -3,6 +3,8 @@ Eclipse4/RCP/EAS/List of All Provided Services
 
 This page provides a listing of the services and other data values that can be injected or obtained from a [context](Eclipse4_RCP_Contexts.md).
 
+> **For detailed information on using ECommandService and EHandlerService**, see [Eclipse4 Commands](Eclipse4_Commands.md).
+
 
 Application Context
 -------------------

docs/Eclipse4_RCP_FAQ.md

@@ -334,6 +334,8 @@ This problem usually occurs in testing, where an object is created explictly via
 Commands and Handlers
 ---------------------
 
+> **Need to execute commands programmatically?** See [Eclipse4 Commands](Eclipse4_Commands.md) for detailed instructions on calling commands using ECommandService and EHandlerService in E4 applications.
+
 ### Why aren't my handler fields being re-injected?
 
 Handler instances are singleton-ish — that is, only a single instance is created within the Eclipse-4 workbench — and the handler may actually be invoked by different threads in parallel. So the handler instance can’t be re-injected since that may result in field clobbering. Only the method arguments of the @CanExecute and @Execute arguments are injected, since they can't be clobbered with parallel invocations.