Deprecate old guides

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

guide/deprecated/asynchronous.md

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+# Guide on Asynchronous processing
+
+Asynchronous function calls can be queued up using the following route:
+
+```
+$ curl --data "message" http://gateway:8080/async-function/{function_name}
+```
+
+Summary of modes for calling functions via API Gateway:
+
+| Mode         | Method | URL                                            | Body | Headers  | Query string
+| -------------|--------|------------------------------------------------|------|--------- |------------------- |
+| Synchronous  | POST   | http://gateway:8080/function/{function_name}        | Yes  | Yes      | Yes |
+| Synchronous  | GET    | http://gateway:8080/function/{function_name}        | Yes  | Yes      | Yes |
+| Asynchronous | POST   | http://gateway:8080/async-function/{function_name}  | Yes  | Yes      | Yes [#369](https://github.com/openfaas/faas/issues/369) |
+| Asynchronous | GET    | Not supported                                  | -    | -        | - |
+
+> Note: This work was originally carried out under [PR #131](https://github.com/openfaas/faas/pull/131).
+
+*Logical flow for synchronous functions:*
+
+![](https://user-images.githubusercontent.com/6358735/29469107-cbc38c88-843e-11e7-9516-c0dd33bab63b.png)
+
+## Why use Asynchronous processing?
+
+* Enable longer time-outs
+
+* Process work whenever resources are available rather than immediately
+
+* Consume a large batch of work within a few seconds and let it process at its own pace
+
+## How does async work?
+
+Here is a conceptual diagram
+
+<img width="1440" alt="screen shot 2017-10-26 at 15 55 19" src="https://user-images.githubusercontent.com/6358735/32060206-047eb75c-ba66-11e7-94d3-1343ea1811db.png">
+
+You can also use asynchronous calls with a callback URL
+
+<img width="1440" alt="screen shot 2017-10-26 at 15 55 06" src="https://user-images.githubusercontent.com/6358735/32060205-04545692-ba66-11e7-9e6d-b800a07b9bf5.png">
+
+The reference implementation for asychronous processing uses NATS Streaming, but you are free to extend OpenFaaS and write your own [queue-worker](https://github.com/open-faas/nats-queue-worker).
+
+> The asynchronous stack is now built-in by default. Previously it was an optional configuration.
+
+## Call a function
+
+Functions do not need to be modified to work asynchronously, just use this alternate route:
+
+```
+http://gateway:8080/async-function/{function_name}
+```
+
+If you want the function to call another function or a different endpoint when it is finished then pass the `X-Callback-Url` header. This is optional.
+
+```
+$ curl http://gateway:8080/async-function/{function_name} --data-binary @sample.json -H "X-Callback-Url: http://gateway:8080/function/send2slack"
+```
+
+You can also use the following site to setup a public endpoint for testing HTTP callbacks: [requestb.in](https://requestb.in)
+
+## Extend function timeouts
+
+Functions have three timeouts configurable by environmental variables expressed in seconds:
+
+HTTP:
+
+* read_timeout
+* write_timeout
+
+Hard timeout:
+
+* exec_timeout
+
+To make use of these just add them to your Dockerfile when needed as ENV variables.
+
+> [Function watchdog reference](https://github.com/openfaas/faas/tree/master/watchdog)