Update 'power-plants.json'

Query 'node' elements with 'power' key and 'plant' tag or 'station' tag :

(node[power=plant];
node[power=station];
way[power=plant];
way[power=station];)

N.B.: power=plant should not be used on nodes
See https://wiki.openstreetmap.org/wiki/Tag:power%3Dplant

N.B.: power=station is deprecated and should not be used for power plants
See https://taginfo.openstreetmap.org/tags/power=station#wiki

power-plants.json

@@ -3,11 +3,13 @@
     "name": {
         "en": "power-plants",
         "de": "kraftwerke",
-        "fr": "centrales-électrique"
+        "fr": "centrales-électriques"
     },
     "query": {
         "7": [
-            "(way[power=plant];",
+            "(node[power=plant];",
+            "node[power=station];",
+            "way[power=plant];",
             "way[power=station];)"
         ]
     }