message: doc aspects (copied material from BisCore.ECSchema)
diff: @@ -6,7 +6,10 @@ import { Entity } from "./Entity";
  import { IModelDb } from "./IModelDb";
  import { ElementAspectProps } from "@bentley/imodeljs-common";
  -/** ElementAspect */
  +/** An Element Aspect is a class that defines a set of properties that are related to (and owned by) a single element.
  + * Semantically, an Element Aspect can be considered part of the Element. Thus, an Element Aspect is deleted if its owning Element is deleted.
  + * BIS Guideline: Subclass ElementUniqueAspect or ElementMultiAspect rather than subclassing ElementAspect directly.
  + */
  export class ElementAspect extends Entity implements ElementAspectProps {
  public element: Id64;
  @@ -16,10 +19,10 @@ export class ElementAspect extends Entity implements ElementAspectProps {
  }
  }
  -/** ElementUniqueAspect */
  +/** An Element Unique Aspect is an Element Aspect where there can be only zero or one instance of the Element Aspect class per Element. See [[IModelDb.getUniqueAspect]] */
  export class ElementUniqueAspect extends ElementAspect {
  }
  -/** ElementMultiAspect */
  +/** An Element Multi-Aspect is an Element Aspect where there can be <em>n</em> instances of the Element Aspect class per Element. See [[IModelDb.getMultiAspects]] */
  export class ElementMultiAspect extends ElementAspect {
  }
  