Revert "docs: split TOC into two parts: overview and API"

This reverts commit cd4cb8e795.

doc/api/_toc.markdown

@@ -1,53 +1,38 @@
-## Overview
+## Table of Contents
 
 * [Synopsis](synopsis.html)
 * [Globals](globals.html)
+* [STDIO](stdio.html)
+* [Timers](timers.html)
 * [Modules](modules.html)
+* [C/C++ Addons](addons.html)
+* [Process](process.html)
+* [Utilities](util.html)
 * [Events](events.html)
 * [Buffers](buffers.html)
 * [Streams](streams.html)
-* [STDIO](stdio.html)
-* [File System](fs.html)
-* [HTTP](http.html)
-* [Process](process.html)
-* [Debugger](debugger.html)
-
-## API
-
-* [Assertion Testing](assert.html)
-* [Buffers](buffers.html)
-* [C/C++ Addons](addons.html)
-* [Child Processes](child_processes.html)
-* [Cluster](cluster.html)
 * [Crypto](crypto.html)
-* [Debugger](debugger.html)
-* [DNS](dns.html)
-* [Events](events.html)
+* [TLS/SSL](tls.html)
+* [String Decoder](string_decoder.html)
 * [File System](fs.html)
-* [Globals](globals.html)
+* [Path](path.html)
+* [Net](net.html)
+* [UDP/Datagram](dgram.html)
+* [DNS](dns.html)
 * [HTTP](http.html)
 * [HTTPS](https.html)
-* [Modules](modules.html)
-* [Net](net.html)
-* [OS](os.html)
-* [Path](path.html)
-* [Process](process.html)
+* [URL](url.html)
 * [Query Strings](querystring.html)
 * [Readline](readline.html)
 * [REPL](repl.html)
-* [STDIO](stdio.html)
-* [Streams](streams.html)
-* [String Decoder](string_decoder.html)
-* [Timers](timers.html)
-* [TLS/SSL](tls.html)
-* [TTY](tty.html)
-* [UDP/Datagram](dgram.html)
-* [URL](url.html)
-* [Utilities](util.html)
 * [VM](vm.html)
+* [Child Processes](child_processes.html)
+* [Assertion Testing](assert.html)
+* [TTY](tty.html)
 * [ZLIB](zlib.html)
-
-## Appendixes
-
-* [Appendix 1: Recommended Third-party Modules](appendix_1.html)
-* [Appendix 2: Deprecated API's](appendix_2.html)
+* [OS](os.html)
+* [Debugger](debugger.html)
+* [Cluster](cluster.html)
+* Appendixes
+  * [Appendix 1: Recommended Third-party Modules](appendix_1.html)
+  * [Appendix 2: Deprecated API's](appendix_2.html)