feat: expose Markdown fields in webhook payload (#14931)

Fixes: https://github.com/coder/coder/issues/14930

docs/admin/notifications/slack.md

@@ -90,9 +90,11 @@ receiver.router.post("/v1/webhook", async (req, res) => {
 			return res.status(400).send("Error: request body is missing");
 		}
 
-		const { title, body } = req.body;
-		if (!title || !body) {
-			return res.status(400).send('Error: missing fields: "title", or "body"');
+		const { title_markdown, body_markdown } = req.body;
+		if (!title_markdown || !body_markdown) {
+			return res
+				.status(400)
+				.send('Error: missing fields: "title_markdown", or "body_markdown"');
 		}
 
 		const payload = req.body.payload;
@@ -118,11 +120,11 @@ receiver.router.post("/v1/webhook", async (req, res) => {
 			blocks: [
 				{
 					type: "header",
-					text: { type: "plain_text", text: title },
+					text: { type: "mrkdwn", text: title_markdown },
 				},
 				{
 					type: "section",
-					text: { type: "mrkdwn", text: body },
+					text: { type: "mrkdwn", text: body_markdown },
 				},
 			],
 		};

docs/admin/notifications/teams.md

@@ -67,10 +67,10 @@ The process of setting up a Teams workflow consists of three key steps:
     				}
     			}
     		},
-    		"title": {
+    		"title_markdown": {
     			"type": "string"
     		},
-    		"body": {
+    		"body_markdown": {
     			"type": "string"
     		}
     	}
@@ -108,11 +108,11 @@ The process of setting up a Teams workflow consists of three key steps:
     		},
     		{
     			"type": "TextBlock",
-    			"text": "**@{replace(body('Parse_JSON')?['title'], '"', '\"')}**"
+    			"text": "**@{replace(body('Parse_JSON')?['title_markdown'], '"', '\"')}**"
     		},
     		{
     			"type": "TextBlock",
-    			"text": "@{replace(body('Parse_JSON')?['body'], '"', '\"')}",
+    			"text": "@{replace(body('Parse_JSON')?['body_markdown'], '"', '\"')}",
     			"wrap": true
     		},
     		{