style index: remove 'unique' in button labels

Buttons said 'unique' too. But after making the lines unique as an
option to check it had to be removed from the button labels. Had to be
removed from the details 'How to sort' too.

Signed-off-by: Conrad Zelck <git@simpel.cc>

index.html

@@ -29,12 +29,12 @@
     <details>
       <summary>How to sort</summary>
       <p>With this tool you can sort newline separated lines alphabetically.</p>
-      <p>You can either push the button "Paste, Sort, Unique &amp; Copy" where the clipboard content is used as content or fill in your lines into textarea and push the button "Sort, Unique &amp; Copy". In both cases the sorted result will be put back to clipboard.</p>
+      <p>You can either push the button "Paste, Sort &amp; Copy" where the clipboard content is used as content or fill in your lines into textarea and push the button "Sort &amp; Copy". In both cases the sorted result will be put back to clipboard.</p>
     </details>
 <div class="flex">
-  <button class="button pastesortunique" title="click: paste + sort + unique + copy to clipboard" onclick="paste()">Paste, Sort, Unique &amp; Copy [1]</button>
+  <button class="button pastesortunique" title="click: paste + sort + unique + copy to clipboard" onclick="paste()">Paste, Sort &amp; Copy [1]</button>
   <span class="between_buttons">or</span>
-  <button class="button sortunique" title="click: sort + unique + copy to clipboard" onclick="sort_and_copy()">Sort, Unique &amp; Copy [2]</button>
+  <button class="button sortunique" title="click: sort + unique + copy to clipboard" onclick="sort_and_copy()">Sort &amp; Copy [2]</button>
   <input id="unique" type="checkbox" name="unique" checked>
   <label for="unique">output unique lines only</label>
 </div>