Added more control structure examples.

Author: artob

README.md

@@ -201,12 +201,16 @@ special semantics that need to be taken into account.
 
     Ruby input                           | PHP output
     -------------------------------------|--------------------------------------
-    return                               | return
-    return $x                            | return $x
     if true then ... else ... end        | if (TRUE) { ... } else { ... }
+    ... if true                          | if (TRUE) { ... }
     unless true then ... else ... end    | if (!TRUE) { ... } else { ... }
+    ... unless true                      | if (!TRUE) { ... }
     while $x; ...; end                   | while ($x) { ... }
+    until $x; ...; end                   | while (!$x) { ... }
     for $x in $y; ...; end               | foreach ($y as $x) { ... }
+    for $k, $v in $z; ...; end           | foreach ($z as $k => $v) { ... }
+    return                               | return
+    return $x                            | return $x
 
 Limitations
 -----------