Make doctool as optional

CMakeLists.txt

@@ -29,7 +29,6 @@ find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS
     Config
     Crash
     DBusAddons
-    DocTools
     WidgetsAddons
     Config
     I18n
@@ -38,6 +37,11 @@ find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS
     Notifications
     NotifyConfig
 )
+find_package(KF5DocTools ${KF5_MIN_VERSION})
+set_package_properties(KF5DocTools PROPERTIES DESCRIPTION
+    "Tools to generate documentation"
+    TYPE OPTIONAL
+)
 
 find_package(KF5KDEGames 7.3.0 REQUIRED)
 
@@ -51,9 +55,13 @@ add_definitions(
 add_subdirectory(src)
 add_subdirectory(sounds)
 add_subdirectory(themes)
-add_subdirectory(doc)
 
 ki18n_install(po)
-kdoctools_install(po)
+
+if(KF5DocTools_FOUND)
+    kdoctools_install(po)
+    add_subdirectory(doc)
+endif()
+
 
 feature_summary(WHAT ALL INCLUDE_QUIET_PACKAGES FATAL_ON_MISSING_REQUIRED_PACKAGES)