Clean up instances of old .form-group (#29321)

site/content/docs/4.3/components/dropdowns.md

@@ -689,15 +689,15 @@ Put a form within a dropdown menu, or make it into a dropdown menu, and use [mar
 {{< example >}}
 <div class="dropdown-menu">
   <form class="px-4 py-3">
-    <div class="form-group">
+    <div class="mb-3">
       <label for="exampleDropdownFormEmail1">Email address</label>
       <input type="email" class="form-control" id="exampleDropdownFormEmail1" placeholder="email@example.com">
     </div>
-    <div class="form-group">
+    <div class="mb-3">
       <label for="exampleDropdownFormPassword1">Password</label>
       <input type="password" class="form-control" id="exampleDropdownFormPassword1" placeholder="Password">
     </div>
-    <div class="form-group">
+    <div class="mb-3">
       <div class="form-check">
         <input type="checkbox" class="form-check-input" id="dropdownCheck">
         <label class="form-check-label" for="dropdownCheck">
@@ -715,15 +715,15 @@ Put a form within a dropdown menu, or make it into a dropdown menu, and use [mar
 
 {{< example >}}
 <form class="dropdown-menu p-4">
-  <div class="form-group">
+  <div class="mb-3">
     <label for="exampleDropdownFormEmail2">Email address</label>
     <input type="email" class="form-control" id="exampleDropdownFormEmail2" placeholder="email@example.com">
   </div>
-  <div class="form-group">
+  <div class="mb-3">
     <label for="exampleDropdownFormPassword2">Password</label>
     <input type="password" class="form-control" id="exampleDropdownFormPassword2" placeholder="Password">
   </div>
-  <div class="form-group">
+  <div class="mb-3">
     <div class="form-check">
       <input type="checkbox" class="form-check-input" id="dropdownCheck2">
       <label class="form-check-label" for="dropdownCheck2">

site/content/docs/4.3/components/modal.md

@@ -523,11 +523,11 @@ Below is a live demo followed by example HTML and JavaScript. For more informati
       </div>
       <div class="modal-body">
         <form>
-          <div class="form-group">
+          <div class="mb-3">
             <label for="recipient-name" class="col-form-label">Recipient:</label>
             <input type="text" class="form-control" id="recipient-name">
           </div>
-          <div class="form-group">
+          <div class="mb-3">
             <label for="message-text" class="col-form-label">Message:</label>
             <textarea class="form-control" id="message-text"></textarea>
           </div>