A tiny addendum to the bbt markers doc

include/bbt-markers.html

@@ -26,3 +26,28 @@
   <img style="width:50%;" width="50%" src="/images/bbt-marker-resets-musical-time.png" alt="The BBT marker resets the musical time">
   <figcaption>The BBT marker resets the musical time</figcaption>
 </figure>
+
+<p>
+  Dragging a BBT marker rigth or left will reset the musical time at a different
+  position on the timeline.
+</p>
+
+<p>
+  Right-clicking on a BBT marker opens a menu with two options:
+  <kbd class="menu">Edit…</kbd> and <kbd class="menu">Remove</kbd>.
+</p>
+
+<p>
+  Choosing <kbd class="menu">Edit…</kbd> opens the
+  <kbd class="menu">Edit Musical Time</kbd> dialog where it's possible to rename
+  the marker and set a different bar and/or beat to reset the musical time to:
+</p>
+
+<figure>
+  <img style="width:50%;" width="50%" src="/images/edit-bbt-marker.png" alt="Edit Musical Time">
+  <figcaption>The Edit Musical Time dialog</figcaption>
+</figure>
+
+<p>
+  Choosing <kbd class="menu">Remove</kbd> deletes the marker.
+</p>