adapt multi-select setting tdescription to explain new Ctrl functionality

Author: LariWa

package.json

@@ -1093,12 +1093,12 @@
 				"git-graph.repository.selectMultipleAuthors": {
 					"type": "boolean",
 					"default": true,
-					"description": "Enables the selection of multiple authors from the Authors dropdown."
+					"description": "Enables the selection of multiple authors from the Authors dropdown. When set to false, you can only select multiple authors by 'Ctrl' (or 'Cmd' on macOS) + click."
 				},
 				"git-graph.repository.selectMultipleBranches": {
 					"type": "boolean",
 					"default": true,
-					"description": "Enables the selection of multiple branches from the Branches dropdown."
+					"description": "Enables the selection of multiple branches from the Branches dropdown.  When set to false, you can only select multiple branches by 'Ctrl' (or 'Cmd' on macOS) + click."
 				},
 				"git-graph.repository.showCommitsOnlyReferencedByTags": {
 					"type": "boolean",