Add MapboxField_holder_small.ss

to get the form field work inside a FieldGroup

templates/Bigfork/SilverStripeMapboxField/MapboxField_holder_small.ss

@@ -0,0 +1,11 @@
+<div id="{$HolderID}" class="fieldholder-small form-group field<% if $extraClass %> {$extraClass}<% end_if %>">
+    <% if $Title %>
+        <label for="{$ID}" id="title-{$ID}" class="form__field-label fieldholder-small-label ">{$Title}</label>
+    <% end_if %>
+    <div class="form__field-holder<% if not $Title %> form__field-holder--no-label<% end_if %>">
+        <%-- TODO: change $MessageType to match Bootstraps alert types, e.g. alert-info, alert-danger etc --%>
+        <% if $Message %><p class="alert {$MessageType}" role="alert" id="message-{$ID}">{$Message}</p><% end_if %>
+        {$Field}
+        <% if $Description %><p class="form__field-description form-text" id="describes-{$ID}">{$Description}</p><% end_if %>
+    </div>
+</div>