feat: update GAPIC samples to be featured in create message guide (#871)

* feat: update GAPIC samples to be featured in create message guide

* Remove test ID

* Fix style

---------

Co-authored-by: pierrick <pierrick@google.com>

chat/client-libraries/cloud/create-message-app-cred.js

@@ -28,7 +28,49 @@ async function main() {
   const request = {
     // Replace SPACE_NAME here.
     parent: 'spaces/SPACE_NAME',
-    message: { text: 'Hello with app credential!' }
+    message: {
+      text: '👋🌎 Hello world! I created this message by calling ' +
+            'the Chat API\'s `messages.create()` method.',
+      cardsV2 : [{ card: {
+        header: {
+          title: 'About this message',
+          imageUrl: 'https://fonts.gstatic.com/s/i/short-term/release/googlesymbols/info/default/24px.svg'
+        },
+        sections: [{
+          header: 'Contents',
+          widgets: [{ textParagraph: {
+              text: '🔡 <b>Text</b> which can include ' +
+                    'hyperlinks 🔗, emojis 😄🎉, and @mentions 🗣️.'
+            }}, { textParagraph: {
+              text: '🖼️ A <b>card</b> to display visual elements' +
+                    'and request information such as text 🔤, ' +
+                    'dates and times 📅, and selections ☑️.'
+            }}, { textParagraph: {
+              text: '👉🔘 An <b>accessory widget</b> which adds ' +
+                    'a button to the bottom of a message.'
+            }}
+          ]}, {
+            header: "What's next",
+            collapsible: true,
+            widgets: [{ textParagraph: {
+                text: "❤️ <a href='https://developers.google.com/workspace/chat/api/reference/rest/v1/spaces.messages.reactions/create'>Add a reaction</a>."
+              }}, { textParagraph: {
+                text: "🔄 <a href='https://developers.google.com/workspace/chat/api/reference/rest/v1/spaces.messages/patch'>Update</a> " +
+                      "or ❌ <a href='https://developers.google.com/workspace/chat/api/reference/rest/v1/spaces.messages/delete'>delete</a> " +
+                      "the message."
+              }
+            }]
+          }
+        ]
+      }}],
+      accessoryWidgets: [{ buttonList: { buttons: [{
+        text: 'View documentation',
+        icon: { materialIcon: { name: 'link' }},
+        onClick: { openLink: {
+          url: 'https://developers.google.com/workspace/chat/create-messages'
+        }}
+      }]}}]
+    }
   };
 
   // Make the request

chat/client-libraries/cloud/create-message-user-cred.js

@@ -30,7 +30,16 @@ async function main() {
   const request = {
     // Replace SPACE_NAME here.
     parent: 'spaces/SPACE_NAME',
-    message: { text: 'Hello with user credential!' }
+    message: {
+      text: '👋🌎 Hello world!' +
+            'Text messages can contain things like:\n\n' +
+            '* Hyperlinks 🔗\n' +
+            '* Emojis 😄🎉\n' +
+            '* Mentions of other Chat users `@` \n\n' +
+            'For details, see the ' +
+            '<https://developers.google.com/workspace/chat/format-messages' +
+            '|Chat API developer documentation>.'
+    }
   };
 
   // Make the request

chat/client-libraries/cloud/package.json

@@ -16,7 +16,6 @@
   "scripts": {
     "create-membership-user-cred-for-app.js": "node ./create-membership-user-cred-for-app.js",
     "create-membership-user-cred.js": "node ./create-membership-user-cred.js",
-    "create-message-app-cred-with-cards.js": "node ./create-message-app-cred-with-cards.js",
     "create-message-app-cred.js": "node ./create-message-app-cred.js",
     "create-message-user-cred-at-mention.js": "node ./create-message-user-cred-at-mention.js",
     "create-message-user-cred-message-id.js": "node ./create-message-user-cred-message-id.js",