Add capacity for school, childcare and kindergarten (#136)

Author: bagage

data/presets/amenity/childcare.json

@@ -12,6 +12,7 @@
     ],
     "moreFields": [
         "baby_feeding",
+        "capacity",
         "email",
         "fax",
         "gnis/feature_id",

data/presets/amenity/kindergarten.json

@@ -9,6 +9,7 @@
         "preschool"
     ],
     "moreFields": [
+        "capacity",
         "email",
         "fax",
         "gnis/feature_id",

data/presets/amenity/school.json

@@ -11,6 +11,7 @@
         "website"
     ],
     "moreFields": [
+        "capacity",
         "charge_fee",
         "email",
         "fax",