Added missing altText prop to ImageProps (Issue #848)

Author: gitbrent

types/index.d.ts

@@ -1239,8 +1239,29 @@ declare namespace PptxGenJS {
 	export type MediaType = 'audio' | 'online' | 'video'
 
 	export interface ImageProps extends PositionProps, DataOrPathProps {
+		/**
+		 * Alt Text value ("How would you describe this object and its contents to someone who is blind?")
+		 * - PowerPoint: [right-click on an image] > "Edit Alt Text..."
+		 */
+		altText?: string
+		/**
+		 * Flip horizontally?
+		 * @default false
+		 */
+		flipH?: boolean
+		/**
+		 * Flip vertical?
+		 * @default false
+		 */
+		flipV?: boolean
 		hyperlink?: HyperlinkProps
-		placeholder?: string // 'body' | 'title' | etc.
+		/**
+		 * Placeholder type
+		 * - values: 'body' | 'header' | 'footer' | 'title' | et. al.
+		 * @example 'body'
+		 * @see https://docs.microsoft.com/en-us/office/vba/api/powerpoint.ppplaceholdertype
+		 */
+		placeholder?: string
 		/**
 		 * Image rotation (degrees)
 		 * - range: -360 to 360
@@ -1282,16 +1303,6 @@ declare namespace PptxGenJS {
 			 */
 			y?: number
 		}
-		/**
-		 * Flip horizontally?
-		 * @default false
-		 */
-		flipH?: boolean
-		/**
-		 * Flip vertical?
-		 * @default false
-		 */
-		flipV?: boolean
 	}
 	/**
 	 * Add media (audio/video) to slide