docs: fix rawparams example by truncating comments

Signed-off-by: Pedro Lamas <pedrolamas@gmail.com>

config/sample-macros.cfg

@@ -175,6 +175,29 @@ gcode:
             sensor.temperature,
             sensor.humidity))}
 
+######################################################################
+# Override M117 command with rawparams
+######################################################################
+
+# The macro below will override the default M117 command to echo the message.
+#
+# It uses the rawparams pseudo-variable that contains the full unparsed
+# parameters that was passed to the M117 command.
+#
+# As this can include comments, we are trimming the text when a `;` or `#` is
+# found, and escaping any existing `"`
+
+[gcode_macro M117]
+rename_existing: M117.1
+gcode:
+  {% if rawparams %}
+    {% set escaped_msg = rawparams.split(';', 1)[0].split('\x23', 1)[0]|replace('"', '\\"') %}
+    SET_DISPLAY_TEXT MSG="{escaped_msg}"
+    RESPOND TYPE=command MSG="{escaped_msg}"
+  {% else %}
+    SET_DISPLAY_TEXT
+  {% endif %}
+
 # SDCard 'looping' (aka Marlin M808 commands) support
 #
 # Support SDCard looping