core(layout-shift-elements): add link to documentation

core/audits/layout-shift-elements.js

@@ -10,8 +10,8 @@ import * as i18n from '../lib/i18n/i18n.js';
 const UIStrings = {
   /** Descriptive title of a diagnostic audit that provides up to the top five elements contributing to Cumulative Layout Shift. */
   title: 'Avoid large layout shifts',
-  /** Description of a diagnostic audit that provides up to the top five elements contributing to Cumulative Layout Shift. */
-  description: 'These DOM elements contribute most to the CLS of the page.',
+  /** Description of a diagnostic audit that provides up to the top five elements contributing to Cumulative Layout Shift. The last sentence starting with 'Learn' becomes link text to additional documentation. */
+  description: 'These DOM elements contribute most to the CLS of the page. [Learn how to improve CLS](https://web.dev/optimize-cls/)',
   /**  Label for a column in a data table; entries in this column will be the amount that the corresponding element contributes to the total CLS metric score. */
   columnContribution: 'CLS Contribution',
 };

core/test/fixtures/fraggle-rock/reports/sample-flow-result.json

@@ -1549,7 +1549,7 @@
           "layout-shift-elements": {
             "id": "layout-shift-elements",
             "title": "Avoid large layout shifts",
-            "description": "These DOM elements contribute most to the CLS of the page.",
+            "description": "These DOM elements contribute most to the CLS of the page. [Learn how to improve CLS](https://web.dev/optimize-cls/)",
             "score": null,
             "scoreDisplayMode": "informative",
             "displayValue": "5 elements found",
@@ -8470,7 +8470,7 @@
           "layout-shift-elements": {
             "id": "layout-shift-elements",
             "title": "Avoid large layout shifts",
-            "description": "These DOM elements contribute most to the CLS of the page.",
+            "description": "These DOM elements contribute most to the CLS of the page. [Learn how to improve CLS](https://web.dev/optimize-cls/)",
             "score": null,
             "scoreDisplayMode": "informative",
             "displayValue": "1 element found",
@@ -15633,7 +15633,7 @@
           "layout-shift-elements": {
             "id": "layout-shift-elements",
             "title": "Avoid large layout shifts",
-            "description": "These DOM elements contribute most to the CLS of the page.",
+            "description": "These DOM elements contribute most to the CLS of the page. [Learn how to improve CLS](https://web.dev/optimize-cls/)",
             "score": null,
             "scoreDisplayMode": "notApplicable",
             "details": {

core/test/results/sample_v2.json

@@ -2259,7 +2259,7 @@
     "layout-shift-elements": {
       "id": "layout-shift-elements",
       "title": "Avoid large layout shifts",
-      "description": "These DOM elements contribute most to the CLS of the page.",
+      "description": "These DOM elements contribute most to the CLS of the page. [Learn how to improve CLS](https://web.dev/optimize-cls/)",
       "score": null,
       "scoreDisplayMode": "informative",
       "displayValue": "5 elements found",