Make it easier to figure out where the current G43 values are stored.

Author: petterreinholdtsen

docs/src/gcode/g-code.adoc

@@ -1392,6 +1392,9 @@ G43 <H->
 
 'G43 Hn' uses the offset for tool n.
 
+The active tool length compensation values are stored in the numbered
+parameters '5401-5409'.
+
 [NOTE]
 'G43 H0' is a little special.  Its behavior is different on random
 tool changer machines and nonrandom tool changer machines (see the

docs/src/gcode/overview.adoc

@@ -311,7 +311,7 @@ example '##2'  means the value of the parameter whose index is the
   Persistent.
 * '5399' - Result of M66 - Check or wait for input. Volatile.
 * '5400' - Tool Number. Volatile.
-* '5401-5409' - Tool Offsets for X, Y, Z, A, B, C, U, V & W. Volatile.
+* '5401-5409' - Tool Offsets for X, Y, Z, A, B, C, U, V & W. Set by G43. Volatile.
 * '5410' - Tool Diameter. Volatile.
 * '5411' - Tool Front Angle. Volatile.
 * '5412' - Tool Back Angle. Volatile.