Update links to Katacoda tutorials to point to official versions

Update links to the Katacoda tutorials to point to the official versions
at https://katacoda.com/tektoncd and update the dashboard scenario naming
to be consistent with other (i.e. drop the redundant `tekton-` from the
name + URL).

content/en/_index.html

@@ -57,7 +57,7 @@ Contribute to Tekton on GitHub.
 
 
 {{% blocks/feature icon="fas fa-chalkboard" title="Try Tekton" %}}
-Learn, explore, and experiment with Tekton using [Tekton Playground](https://www.katacoda.com/ratrosyu/scenarios/playground).
+Learn, explore, and experiment with Tekton using [Tekton Playground](https://katacoda.com/tektoncd/scenarios/playground).
 {{% /blocks/feature %}}
 
 

content/en/docs/Getting Started/_index.md

@@ -7,9 +7,7 @@ description: >
 ---
 
 {{% tutorial name="Getting started with Tekton"
-             katacoda-src="ratrosyu/getting-started"
-             github-lnk="michaelawyu/tekton-examples/tree/master/getting-started"
-             qwiklabs-lnk="" %}}
+             katacoda-lnk="https://katacoda.com/tektoncd/scenarios/getting-started" %}}
 
 ## Prerequisites
 

layouts/shortcodes/tutorial.html

@@ -2,7 +2,7 @@
 <div class="alert alert-success" role="alert">
     <h4 class="alert-heading">Note</h4>
     <p>See also the <b>{{ .Get "name" | safeHTML }}</b> interactive tutorial.</p>
-    <a href="https://katacoda.com/ncskier/scenarios/tekton-dashboard" target="_blank" rel="noopener" type="button">
+    <a href={{ .Get "katacoda-lnk" }} target="_blank" rel="noopener" type="button">
         <div class="btn btn-success" type="button">Launch Interactive Tutorial</div>
     </a>
     {{ partial "tutorial-modal.html" }}

layouts/try/baseof.html

@@ -48,7 +48,7 @@
             <div class="col-lg-8 mr-2 ml-2">
                 <div class="row">
                     <div class="col-md-4 pl-1 pr-1 pb-3">
-                        <a href="https://katacoda.com/ncskier/scenarios/tekton-dashboard" target="_blank" rel="noopener">
+                        <a href="https://katacoda.com/tektoncd/scenarios/dashboard" target="_blank" rel="noopener">
                             <article  class="card card-custom-style"
                                 style="background-color: hsl(171, 100%, 41%)">
                                 <div class="card-img-top">