make things clearer in proximity (home-assistant#31208)

Co-authored-by: Franck Nijhof <[email protected]>

source/_integrations/proximity.markdown

@@ -30,12 +30,12 @@ The following sensor entities will be created.
 
 ### Distance
 
-For each tracked device or person, a sensor showing the distance from the monitored zone in a unit depending on your [Home Assistant Unit System](/docs/configuration/basic) selection is created.
+For each tracked [device](/integrations/device_tracker/) or [person](/integrations/person/), a sensor is created showing the distance from the monitored zone in a unit depending on your [Home Assistant Unit System](/docs/configuration/basic) selection. When a tracked person or device enters the monitored zone, the distance is set to 0.
 You can use the [Min/Max](/integrations/min_max) integration to determine the nearest and furthest distance.
 
 ### Direction of travel
 
-For each tracked device or person, a sensor showing the direction of travel to or from the monitored zone is created. Possible states are:
+For each tracked device or person, a sensor is created showing the direction of travel to or from the monitored zone. Possible states are:
 
 - `arrived`
 - `away_from`
@@ -45,4 +45,8 @@ For each tracked device or person, a sensor showing the direction of travel to o
 
 ### Nearest device
 
-A sensor showing the device or person which is nearest to the monitored zone is created.
+A sensor is created showing the device or person which is nearest (_shortest distance_) to the monitored zone. If several devices or persons are at the same nearest distance, this sensor displays them all.
+
+<div class="note">
+To calculate the distance and the direction of travel for a tracked device or person, they must specify a geo-location.
+</div>