cmdline.md: add the section TOC

cmdline.md

@@ -15,3 +15,14 @@ pass on that crazy data in its transfer operation.
 This is a design choice, as it allows you to really tweak how curl does its
 protocol communications and you can have curl massage your server
 implementations in the most creative ways.
+
+  * [Differences](cmdline/differences.md)
+  * [Command line options](cmdline/options.md)
+  * [Options depend on version](cmdline/versions.md)
+  * [URLs](cmdline/urls.md)
+  * [URL globbing](cmdline/globbing.md)
+  * [List options](cmdline/listopts.md)
+  * [Config file](cmdline/configfile.md)
+  * [Variables](cmdline/variables.md)
+  * [Passwords](cmdline/passwords.md)
+  * [Progress meter](cmdline/progressmeter.md)