Theme format refactoring: move line properties into a seperate lineRendering configuration

assets/themes/speelplekken/speelplekken.json

@@ -42,6 +42,12 @@
           "location": [
             "point"
           ]
+        },
+        {
+          "color": "#444444",
+          "width": {
+            "render": "1"
+          }
         }
       ]
     },
@@ -266,6 +272,24 @@
           "location": [
             "point"
           ]
+        },
+        {
+          "color": {
+            "render": "#6d6",
+            "mappings": [
+              {
+                "if": "color~*",
+                "then": "{color}"
+              },
+              {
+                "if": "colour~*",
+                "then": "{colour}"
+              }
+            ]
+          },
+          "width": {
+            "render": "9"
+          }
         }
       ]
     }