Reworked the push/pull trimming

include/pushpull-trimming.html

@@ -1,36 +1,42 @@
 
 <p>
-  Normally, when you trim regions by dragging with the mouse, it affects
+  Normally, when trimming regions by dragging with the mouse, it affects
   only the selected regions. Their lengths are directly affected by the
-  trim operation, but nothing else is. Sometimes though, you might like
-  to trim a region that directly adjoins another, and keep this relationship
-  the same&mdash;you are not trying to make one of the regions extend
-  over the other&mdash;you would like the junction to move in one
-  direction or the other as part of the trim. This requires trimming both
+  trim operation, but nothing else is. Sometimes though, when trimming a region
+  that directly adjoins another, the desired result is to move the boundary
+  between the regions and not to make these regions overlap. This requires trimming both
   regions on either side of the junction, in opposite directions.
-  <dfn>Push/Pull trim</dfn>, activated by pressing shift key before
-  starting the drag, will do just that. Here's a few pictures to show the
-  difference in the results of a normal trim and push/pull trim. First,
-  the initial situation:
+  <dfn>Push/Pull trim</dfn>, activated by pressing <kbd class="mod3n"></kbd> key before
+  starting the drag, will do just that.
 </p>
-<img src="/images/a3_before_trim.png" alt="region arrangement before trim" />
-<p>
-  Here is what happens after we trim the right hand (selected) region by
-  dragging its starting position earlier:
 </p>
-<img src="/images/a3_after_trim.png" alt="region arrangement after a trim" />
-<p>
-  You can see that it now overlaps the earlier region and a crossfade has
-  been created between them.
-</p>
-<p>
-  Lets look now at what happens if we do the same trim, but <kbd
-  class="mouse mod3">Left</kbd>-dragging to turn it into a push-pull trim instead:
-</p>
-<img src="/images/a3_after_push_trim.png" alt="region arrangement after a push trim" />
-<p>
-  There is no overlap, and the end of the earlier region has been moved
-  along with the start of the later region, so that they still directly
-  adjoin each other.
+  The following pictures show the difference in the results of a normal trim and
+  a push/pull trim:
 </p>
 
+<figure>
+  <img src="/images/before-trim.png" alt="region arrangement before trim" />
+  <img src="/images/after-trim.png" alt="region arrangement after a trim" />
+  <img src="/images/after-push-trim.png" alt="region arrangement after a push trim" />
+  <figcaption>
+    Trimming vs. push/pull trimming. Before trimming, After a simple trim, After a push/pull trim
+  </figcaption>
+</figure>
+
+<p>
+  In the initial situation, before trimming, two adjascent regions are present,
+  the rightmost-one being selected.
+</p>
+<p>
+  The simple trim, obtained by dragging the selected region's starting position earlier, overlaps
+  the earlier region. A crossfade has been manually created between them, so their
+  sound will fade from the leftmost region to the rightmost one.
+</p>
+<p>
+  If the same trim is done, but by <kbd class="mod3n"></kbd><kbd class="mouse">Left</kbd>-dragging
+  to turn it into a push-pull trim instead, there is no overlap, and the end of
+  the earlier region has been moved along with the start of the later region, so
+  that they still directly adjoin each other. In effect, it is like doing a simple
+  trim to reduce the leftmost region, then doing a simple trim to extend the rightmost
+  one to fill the gap.
+</p>