Updates changelog and upgrading docs

Author: LordHepipud

doc/30-upgrading-framework.md

@@ -4,9 +4,9 @@ Upgrading Icinga PowerShell Framework is usually quite straightforward.
 
 Specific version upgrades are described below. Please note that version updates are incremental.
 
-## Upgrading to v1.4.0 (pending)
+## Upgrading to v1.4.0 (2021-03-02)
 
-*No special steps required*
+The pre-compiled configurations for each module and the result of `Get-IcingaCheckCommandConfig` have been changed. In order to use the new CheckCommand definitions for Icinga 2 you will **require** to update your entire environment to Icinga for Windows v1.4.0 **before** using the new configuration files!
 
 ## Upgrading to v1.3.0 (2020-12-01)
 

doc/31-Changelog.md

@@ -11,6 +11,10 @@ Released closed milestones can be found on [GitHub](https://github.com/Icinga/ic
 
 [Issue and PRs](https://github.com/Icinga/icinga-powershell-framework/milestone/11?closed=1)
 
+### Breaking Changes
+
+There are changes made to the pre-compiled configuration files and `Get-IcingaCheckCommandConfig.` Please have a look on the [upgrading](30-upgrading-framework.md) before applying the new configuration files.
+
 ### Enhancements
 
 * [#180](https://github.com/Icinga/icinga-powershell-framework/pull/180) Ensure check data are separated from each thread and not accessible from one thread to another to prevent conflicting results