Add note: Semantics defined only for canonical sat/dsat

Prevent reader confusion, as described in sipa#42 where the sematics of "andor" differs from expected by the reader when they consider various executions of the actual script

index.html

@@ -190,7 +190,7 @@ <h4>Translation table</h4>
 <div class="table-responsive">
 <table class="table table-sm">
 <thead class="thead-light">
-<tr><th scope="col">Semantics</th><th scope="col">Miniscript fragment</th><th scope="col">Bitcoin Script</th></tr></thead>
+<tr><th scope="col">Semantics<sup>*</sup></th><th scope="col">Miniscript fragment</th><th scope="col">Bitcoin Script</th></tr></thead>
 <tbody>
 <tr>
   <td>false</td>
@@ -333,6 +333,10 @@ <h4>Translation table</h4>
   <td><code>u:<em>X</em></code> = <code>or_i(<em>X</em>,0)</code></td>
   <td><samp>IF <em>[X]</em> ELSE 0 ENDIF</samp></td>
 </tr>
+<tr><td colspan=3>
+<div class="text-muted">[*] Semantics are defined for canonical satisfaction/dissatisfaction options, and may not be valid for non-canonical options (see "Satisfaction and malleability", "Basic satisfactions" below)</div>
+</td>
+</tr>
 </tbody>
 </table>
 </div>