Add improved type for linkTarget as string

Reviewed-by: Christian Murphy <[email protected]>
Reviewed-by: Titus Wormer <[email protected]>

Closes GH-639.

Author: casperiv0

lib/ast-to-react.js

@@ -32,11 +32,13 @@
  * @param {string?} title
  * @returns {string}
  *
+ * @typedef {import("react").HTMLAttributeAnchorTarget} TransformLinkTargetType
+ *
  * @callback TransformLinkTarget
  * @param {string} href
  * @param {Array.<ElementContent>} children
  * @param {string?} title
- * @returns {string|undefined}
+ * @returns {TransformLinkTargetType|undefined}
  *
  * @typedef {keyof JSX.IntrinsicElements} ReactMarkdownNames
  *
@@ -94,7 +96,7 @@
  * @property {boolean} [includeElementIndex=false]
  * @property {null|false|TransformLink} [transformLinkUri]
  * @property {TransformImage} [transformImageUri]
- * @property {string|TransformLinkTarget} [linkTarget]
+ * @property {TransformLinkTargetType|TransformLinkTarget} [linkTarget]
  * @property {Components} [components]
  */