Update doc links on About page

The overview and concepts documentation has been updated and
reorganised recently. The old overview link is now returning
a 404, update to point to the new location. Also update the
concepts link to point at the concept model page.

src/containers/About/About.js

@@ -231,11 +231,11 @@ export function About({ intl }) {
           <h2 className="tkn--section-title">
             {intl.formatMessage({
               id: 'dashboard.about.documentation',
-              defaultMessage: 'Documentation'
+              defaultMessage: 'Documentation and resources'
             })}
           </h2>
         </header>
-        <ClickableTile href="https://tekton.dev/docs/overview/">
+        <ClickableTile href="https://tekton.dev/docs/concepts/overview/">
           <div className="tkn--about-pictogram">
             <DocsPictogram />
           </div>
@@ -245,13 +245,13 @@ export function About({ intl }) {
             <ArrowIcon className="tkn--about-arrow" />
           </div>
         </ClickableTile>
-        <ClickableTile href="https://tekton.dev/docs/concepts/">
+        <ClickableTile href="https://tekton.dev/docs/concepts/concept-model/">
           <div className="tkn--about-pictogram">
             <DocsPictogram />
           </div>
           <div className="tkn--about-docs-description">
-            <h3>Concepts</h3>
-            <p>Technical information and architecture</p>
+            <h3>Concept model</h3>
+            <p>Basic Tekton components and data model</p>
             <ArrowIcon className="tkn--about-arrow" />
           </div>
         </ClickableTile>

src/nls/messages_en.json

@@ -16,7 +16,7 @@
     "carbon.table.row.select": "Select row",
     "carbon.table.row.unselect": "Unselect row",
     "dashboard.about.description": "Tekton is a powerful and flexible open-source framework for creating CI/CD systems, allowing developers to build, test, and deploy across cloud providers and on-premises systems.",
-    "dashboard.about.documentation": "Documentation",
+    "dashboard.about.documentation": "Documentation and resources",
     "dashboard.about.environmentDetails": "Environment details",
     "dashboard.about.error": "Error getting data",
     "dashboard.about.isReadOnly": "ReadOnly",