- Refactoring: Avoid unnecessary addEventListener false; change internal

jPicker function to class (used with `new`)
- Linting (ESLint): Add `valid-jsdoc` rule and make fixes; but turn off for
  now due to <https://github.com/eslint/eslint/issues/11036> and
  <https://github.com/eslint/eslint/issues/11037>
- Docs (JSDoc): Add some Markdown for variables, line breaks; tighten checks
  for overly generic types (though allow for `.Function` as in
  `jQuery.Function`) and avoid one previously missed instance

editor/draw.js

@@ -67,7 +67,7 @@ function getNewLayerName (existingLayerNames) {
 }
 
 /**
- * This class encapsulates the concept of a SVG-edit drawing
+ * This class encapsulates the concept of a SVG-edit drawing.
  */
 export class Drawing {
   /**
@@ -184,7 +184,7 @@ export class Drawing {
   }
 
   /**
-   * Clears any previously set nonce
+   * Clears any previously set nonce.
    * @returns {undefined}
    */
   clearNonce () {
@@ -276,7 +276,7 @@ export class Drawing {
   }
 
   /**
-   * Check if layer with given name already exists
+   * Check if layer with given name already exists.
    * @param {string} name - The layer name to check
    * @returns {boolean}
   */
@@ -302,6 +302,7 @@ export class Drawing {
 
   /**
    * Get a layer by name.
+   * @param {string} name
    * @returns {SVGGElement} The SVGGElement representing the named layer or null.
    */
   getLayerByName (name) {
@@ -663,7 +664,7 @@ export class Drawing {
   }
 
   /**
-   * Create a clone of an element, updating its ID and its children's IDs when needed
+   * Create a clone of an element, updating its ID and its children's IDs when needed.
    * @param {Element} el - DOM element to clone
    * @returns {Element}
    */
@@ -767,7 +768,7 @@ export const init = function (canvas) {
 };
 
 /**
-* Updates layer system
+* Updates layer system.
 * @function module:draw.identifyLayers
 * @returns {undefined}
 */
@@ -980,7 +981,7 @@ export const mergeAllLayers = function (hrService) {
 
 /**
 * Return from a group context to the regular kind, make any previously
-* disabled elements enabled again
+* disabled elements enabled again.
 * @function module:draw.leaveContext
 * @fires module:svgcanvas.SvgCanvas#event:contextset
 * @returns {undefined}
@@ -1006,7 +1007,7 @@ export const leaveContext = function () {
 };
 
 /**
-* Set the current context (for in-group editing)
+* Set the current context (for in-group editing).
 * @function module:draw.setContext
 * @param {Element} elem
 * @fires module:svgcanvas.SvgCanvas#event:contextset