Correct endstop noise comment

Marlin/Configuration.h

  * Enable if your probe or endstops falsely trigger due to noise.
  *
  * - Higher values may affect repeatability or accuracy of some bed probes.
- * - To fix noise install a 100nF ceramic capacitor inline with the switch.
+ * - To fix noise install a 100nF ceramic capacitor in parallel with the switch.
  * - This feature is not required for common micro-switches mounted on PCBs
  *   based on the Makerbot design, which already have the 100nF capacitor.
  *