Simple index pages for docc (#170)

Motivation:

An index page ties all the other documentation together

Modifications:

Add index pages for the library targets.
Correct a few minor errors in the main docs.

Result:

A more joined up documentation experience.

Sources/NIOExtras/Docs.docc/index.md

@@ -0,0 +1,43 @@
+# ``NIOExtras``
+
+A collection of helpful utilities to assist in building and debugging Swift-NIO based applications.
+
+## Overview
+
+A collection of helpful utilities to assist in building and debugging Swift-NIO based applications.  Topics covered include packet capture, the logging of channel pipeline events, frame decoding of various common forms and helpful data types.
+
+Debugging aids include `ChannelHandler`s to log channel pipeline events both inbound and outbound; and a `ChannelHandler` to log data in packet capture format.
+
+To support encoding and decoding helpers are provided for data frames which have fixed length; are new line terminated; contain a length prefix; or are defined by a `context-length` header.
+
+To help simplify building a robust pipeline the ``ServerQuiescingHelper`` makes it easy to collect all child `Channel`s that a given server `Channel` accepts.
+
+Easy request response flows can be built using the ``RequestResponseHandler`` which takes a request and a promise which is fulfilled when an expected response is received.
+
+## Topics
+
+### Debugging Aids
+
+- ``DebugInboundEventsHandler``
+- ``DebugOutboundEventsHandler``
+- ``NIOWritePCAPHandler``
+- ``NIOPCAPRingBuffer``
+
+### Encoding and Decoding
+
+- ``FixedLengthFrameDecoder``
+- ``NIOJSONRPCFraming``
+- ``LengthFieldBasedFrameDecoder``
+- ``NIOLengthFieldBasedFrameDecoderError``
+- ``LengthFieldPrepender``
+- ``LengthFieldPrependerError``
+- ``LineBasedFrameDecoder``
+- ``NIOExtrasErrors``
+- ``NIOExtrasError``
+
+### Channel Pipeline Aids
+- ``ServerQuiescingHelper``
+- ``RequestResponseHandler``
+
+### Data Types
+- ``NIOLengthFieldBitLength``

Sources/NIOExtras/WritePCAPHandler.swift

@@ -184,7 +184,7 @@ public class NIOWritePCAPHandler: RemovableChannelHandler {
     private var localAddress: SocketAddress?
     private var remoteAddress: SocketAddress?
 
-    /// Reusable header for `. pcap` file.
+    /// Reusable header for `.pcap` file.
     public static var pcapFileHeader: ByteBuffer {
         var buffer = ByteBufferAllocator().buffer(capacity: 24)
         buffer.writePCAPHeader()

Sources/NIOHTTPCompression/Docs.docc/index.md

@@ -0,0 +1,27 @@
+# ``NIOHTTPCompression``
+
+Automatic compression and decompression of HTTP data.
+
+## Overview
+
+Channel handlers to support automatic compression and decompression of HTTP data.  Add the handlers to your pipeline to support the features you need.
+
+`Content-Encoding`, `Content-Length`, and `accept-encoding` HTTP headers are set and respected where appropriate.
+
+Be aware that this works best if there is sufficient data written between flushes.  This also performs compute on the event loop thread which could impact performance.
+
+## Topics
+
+### Client Channel Handlers
+
+- ``NIOHTTPRequestCompressor``
+- ``NIOHTTPResponseDecompressor``
+
+### Server Channel Handlers
+- ``NIOHTTPRequestDecompressor``
+- ``HTTPResponseCompressor``
+
+### Compression Methods
+
+- ``NIOCompression``
+- ``NIOHTTPDecompression``

Sources/NIOHTTPCompression/HTTPDecompression.swift

@@ -15,6 +15,7 @@
 import CNIOExtrasZlib
 import NIOCore
 
+/// Namespace for decompression code.
 public enum NIOHTTPDecompression {
     /// Specifies how to limit decompression inflation.
     public struct DecompressionLimit {

Sources/NIOSOCKS/Docs.docc/index.md

@@ -0,0 +1,35 @@
+# ``NIOSOCKS``
+
+SOCKS v5 protocol implementation
+
+## Overview
+
+An implementation of SOCKS v5 protocol.  See [RFC1928](https://www.rfc-editor.org/rfc/rfc1928).
+
+Add the appropriate channel handler to the start of your channel pipeline to use this protocol.
+
+For an example see the NIOSOCKSClient target.
+
+## Topics
+
+### Channel Handlers
+- ``SOCKSClientHandler``
+- ``SOCKSServerHandshakeHandler``
+
+### Client Messages
+- ``ClientMessage``
+- ``ClientGreeting``
+- ``SOCKSRequest``
+
+### Server Messages
+- ``ServerMessage``
+- ``SelectedAuthenticationMethod``
+- ``SOCKSResponse``
+
+### Supporting Types
+- ``AuthenticationMethod``
+- ``SOCKSServerReply``
+- ``SOCKSCommand``
+- ``SOCKSAddress``
+- ``SOCKSProxyEstablishedEvent``
+- ``SOCKSError``