Add some docs to note.js (for backend scripting docs)

src/becca/entities/note.js

@@ -1018,6 +1018,13 @@ class Note extends AbstractEntity {
     }
 
     /**
+     * Adds a new attribute to this note. The attribute is saved and returned.
+     * See addLabel, addRelation for more specific methods.
+     *
+     * @param {string} type - attribute type (label / relation)
+     * @param {string} name - name of the attribute, not including the leading ~/#
+     * @param {string} [value] - value of the attribute - text for labels, target note ID for relations; optional.
+     *
      * @return {Attribute}
      */
     addAttribute(type, name, value = "", isInheritable = false, position = 1000) {
@@ -1033,10 +1040,27 @@ class Note extends AbstractEntity {
         }).save();
     }
 
+    /**
+     * Adds a new label to this note. The label attribute is saved and returned.
+     *
+     * @param {string} name - name of the label, not including the leading #
+     * @param {string} [value] - text value of the label; optional
+     *
+     * @return {Attribute}
+     */
     addLabel(name, value = "", isInheritable = false) {
         return this.addAttribute(LABEL, name, value, isInheritable);
     }
 
+    /**
+     * Adds a new relation to this note. The relation attribute is saved and
+     * returned.
+     *
+     * @param {string} name - name of the relation, not including the leading ~
+     * @param {string} value - ID of the target note of the relation
+     *
+     * @return {Attribute}
+     */
     addRelation(name, targetNoteId, isInheritable = false) {
         return this.addAttribute(RELATION, name, targetNoteId, isInheritable);
     }