execCommand: use range's collapsed concept instead of public API

Author: annevk

docs/execCommand/index.html

@@ -2242,7 +2242,7 @@ <h3 id="inline-formatting-command-definitions">
           "concept-node">node</a> <var title="">node</var> is <dfn id=
           "effectively-contained">effectively contained</dfn> in a [=range=]
           <var title="">range</var> if <var title="">range</var> is not
-          {{AbstractRange/collapsed}}, and at least one of the following holds:
+          [=range/collapsed=], and at least one of the following holds:
         </p>
         <ul>
           <li>
@@ -5634,7 +5634,7 @@ <h3 id="block-formatting-command-definitions">
           its <a href="#action">action</a>, the user agent must <a href=
           "#record-current-overrides">record current overrides</a>. After
           taking the <a href="#action">action</a>, if the <a href=
-          "#active-range">active range</a> is {{AbstractRange/collapsed}}, it
+          "#active-range">active range</a> is [=range/collapsed=], it
           must <a href="#restore-states-and-values">restore states and
           values</a> from the recorded list.
         </p>
@@ -11077,7 +11077,7 @@ <h3 id="the-delete-command">
         </p>
         <ol>
           <li>If the <a href="#active-range">active range</a> is not
-          {{AbstractRange/collapsed}}, <a href="#delete-the-selection">delete
+          [=range/collapsed=], <a href="#delete-the-selection">delete
           the selection</a> and return true.
           </li>
           <li>
@@ -12251,7 +12251,7 @@ <h3 id="the-forwarddelete-command">
         </p>
         <ol>
           <li>If the <a href="#active-range">active range</a> is not
-          {{AbstractRange/collapsed}}, <a href="#delete-the-selection">delete
+          [=range/collapsed=], <a href="#delete-the-selection">delete
           the selection</a> and return true.
           </li>
           <li>