clarify table heading (#1507)

Author: sanscontext

src/connections/spec/ecommerce/v2.md

@@ -417,7 +417,7 @@ This event supports the following semantic properties:
     <td>**Property**</td>
     <td>**Type**</td>
     <td>**Description**</td>
-    <td>**Type**</td>
+    <td>**Example**</td>
   </tr>
   <tr>
     <td>promotion_id</td>
@@ -469,7 +469,7 @@ This event supports the following semantic properties:
     <td>**Property**</td>
     <td>**Type**</td>
     <td>**Description**</td>
-    <td>**Type**</td>
+    <td>**Example**</td>
   </tr>
   <tr>
     <td>promotion_id</td>