feat: update chapter 6 of BG

docs/pilots-corner/a380x/a380x-beginner-guide/.pages

@@ -11,7 +11,7 @@ nav:
     - Preparing FMS: 03_preparing-fms.md
     - Engine Start and Taxi: 04_engine-start-taxi.md
     - Takeoff, Climb & Cruise: 05_takeoff-climb-cruise.md
-    #- 06_descent.md
+    - Descent Planning and Descent: 06_descent.md
     #- 07_landing.md
     #- 08_after-landing.md
     #- 09_powering-down.md

docs/pilots-corner/a380x/a380x-beginner-guide/05_takeoff-climb-cruise.md

@@ -468,10 +468,22 @@ This concludes the *Climb*.
 - Aircraft has leveled off at planned cruise level.
 - Speed is cruise speed as per ECAM PERF CRZ page.
 
+`ALT CRZ on flight mode annunciator ................................. CHECK`<br/>
+??? note "Cruise Phase"
+    The FMA now shows `ALT CRZ` in white in the second column of the FMA (Vertical Guidance). This means the aircraft is
+    in cruise mode and will maintain the selected altitude.
+
+    Verify that the aircraft is cruising on the cruise flight level inserted on the CRZ panel of the flight management 
+    system of the active performance page. This will ensure that the aircraft flies at the targeted cruise speed so fuel 
+    consumptions is optimized. This will also benefit to a soft autothrottle mode, as well have more accurate predictions.
 
 This is usually the quietest time of the flight. It allows time to double-check the systems by going through all ECAM
 pages, etc.
 
+`ECAM MEMO ......................................................... REVIEW`<br/>
+`SD PAGES .......................................................... REVIEW`<br/>
+`FLIGHT PROGRESS .................................................. MONITOR`<br/>
+
 Regular ATC frequency changes with altitude and position check-ins are common.
 
 Here are some **typical activities** which might happen during cruise mostly on request from ATC or other circumstances