docs: Update Styling docs for new 'plugin-tasks-toolbar' div

This contains 'test-icon' and 'test-tooltip' values which may confuse users...

Author: claremacrae

docs/snippets-embedded-in-multiple-pages/Sample HTML - Full mode.md

@@ -5,7 +5,7 @@
 -->
 
 <div>
-  <button class="plugin-tasks-copy-button">Copy results</button>
+  <div class="plugin-tasks-toolbar"><button test-icon="lucide-copy" test-tooltip="Copy results"></button></div>
   <ul class="contains-task-list plugin-tasks-query-result">
     <li
       class="task-list-item plugin-tasks-list-item"

docs/snippets-embedded-in-multiple-pages/Sample HTML - Short mode.md

@@ -5,7 +5,7 @@
 -->
 
 <div>
-  <button class="plugin-tasks-copy-button">Copy results</button>
+  <div class="plugin-tasks-toolbar"><button test-icon="lucide-copy" test-tooltip="Copy results"></button></div>
   <ul class="contains-task-list plugin-tasks-query-result tasks-layout-short-mode">
     <li
       class="task-list-item plugin-tasks-list-item"