Partially fix themes

src/Models/ThemeConfig/Conversion/Validation.ts

@@ -1061,10 +1061,20 @@ export class PrevalidateLayer extends DesugaringStep<LayerConfigJson> {
                         "'"
                 )
         }
+        if (json["pointRenderings"]?.length > 0) {
+            context
+                .enter("pointRenderings")
+                .err("Detected a 'pointRenderingS', it is written singular")
+        }
 
         if (!(json.pointRendering?.length > 0)) {
             // context.enter("pointRendering").err("There are no pointRenderings at all")
         }
+
+        if (json["mapRendering"]) {
+            context.enter("mapRendering").err("This layer has a legacy 'mapRendering'")
+        }
+
         if (json.presets?.length > 0) {
             if (!(json.pointRendering?.length > 0)) {
                 context.enter("presets").warn("A preset is defined, but there is no pointRendering")

src/Models/ThemeConfig/PointRenderingConfig.ts

@@ -85,6 +85,12 @@ export default class PointRenderingConfig extends WithContextLoader {
             throw `At ${context}: A point rendering should define at least an marker or a label`
         }
 
+        if (json["markers"]) {
+            throw `At ${context}.markers: detected a field 'markerS' in pointRendering. It is written as a singular case`
+        }
+        if (json.marker && !Array.isArray(json.marker)) {
+            throw `At ${context}.marker: the marker in a pointRendering should be an array`
+        }
         if (this.location.size == 0) {
             throw (
                 "A pointRendering should have at least one 'location' to defined where it should be rendered. (At " +