add :optionusage command

content/liberator.js

@@ -349,6 +349,34 @@ const liberator = (function () //{{{
                 bangAllowed: true
             });
 
+        liberator.commands.add(["optionu[sage]"],
+            "List all options with a short description",
+            function (args, special)
+            {
+                if (!special)
+                {
+                    liberator.help("option-index");
+                }
+                else
+                {
+                    // TODO: clicking on these should open the help
+                    var usage = <table>
+                        {
+                            liberator.template.map(liberator.options, function (option)
+                            <tr>
+                                <td class="hl-Title" style="padding-right: 20px">{option.name}</td>
+                                <td>{option.description}</td>
+                            </tr>)
+                        }
+                        </table>;
+                    liberator.echo(usage, liberator.commandline.FORCE_MULTILINE);
+                }
+            },
+            {
+                argCount: "0",
+                bangAllowed: true
+            });
+
         liberator.commands.add(["q[uit]"],
             liberator.has("tabs") ? "Quit current tab" : "Quit application",
             function (args, special)

content/options.js

@@ -862,8 +862,9 @@ liberator.Options = function () //{{{
 
         __iterator__: function ()
         {
-            for (let i = 0; i < options.length; i++)
-                yield options[i];
+            let sorted = options.sort(function (opt1, opt2) opt1.name > opt2.name);
+            for (let i = 0; i < sorted.length; i++)
+                yield sorted[i];
         },
 
         add: function (names, description, type, defaultValue, extraInfo)