Tweak comments

Marlin/Marlin_main.cpp

  * M405 - Turn on Filament Sensor extrusion control.  Optional D<delay in cm> to set delay in centimeters between sensor and extruder
  * M406 - Turn off Filament Sensor extrusion control
  * M407 - Display measured filament diameter
- * M410 - Quickstop - Abort all the planned moves
+ * M410 - Quickstop. Abort all the planned moves
  * M500 - Store parameters in EEPROM
  * M501 - Read parameters from EEPROM (if you need reset them after you changed them temporarily).
  * M502 - Revert to the default "factory settings". You still need to store them in EEPROM afterwards if you want to.
 #endif // FILAMENT_SENSOR
 
 /**
- * M410: quickstop - Abort all planned moves
+ * M410: Quickstop - Abort all planned moves
  *
  * This will stop the carriages mid-move, so most likely they
  * will be out of sync with the stepper position after this.