[WIP] Add quickstart guide for ohttp-relay on basic ubuntu server

This issue payjoin/ohttp-relay#37 outlines
a need for some documentation for a quickstart guide on a docker server
with a nginx proxy.

Author: benalleng

docs/tutorials/quickstart-ohttp-relay.md

@@ -0,0 +1,94 @@
+# Quickstart ohttp relay
+
+We'll demonstrate how you can setup an ohttp server on common cloud insfrastructure on something like [AWS Ubunut](https://docs.aws.amazon.com/kinesisvideostreams/latest/dg/gs-ubuntu.html) using the `ohttp-relay` crate in Payjoin Dev Kit. This should take about 30 minutes.
+
+## Initial server setup
+
+We will be using a basic Ubuntu server in our tutorial. In this tutorial we will be running the server as a docker container with nginx as a TLS proxy.
+
+First, you must install docker and nginx on your server.
+
+Install docker, nginx and the ningx stream module on a fresh Ubuntu server:
+
+```sh
+sudo apt update && sudo apt upgrade -y # Ubuntu
+
+sudo apt install -y docker.io nginx libnginx-mod-stream #This lib will give us access to the nginx stream module
+
+sudo systemctl start docker nginx
+sudo systemctl enable docker nginx
+```
+
+## Deploy ohttp-relay with Docker
+
+We will want to build our docker image for our server to run as a container from.
+
+Clone our ohttp-relay from github and then build the docker image.
+
+```sh
+git clone https://github.com/payjoin/ohttp-relay.git
+
+cd ohttp-relay
+
+sudo docker build -t ohttp-relay .
+```
+
+## Configure Nginx as a Reverse Proxy
+
+Edit the existing `nginx.conf`.
+
+```sh 
+#/etc/nginx/nginx.conf
+load_modules /usr/lib/nginx/modules/ngx_mod_stream.so;
+error_log /var/log/nginx/error.log debug;
+pid /var/run/nginx.pid;
+
+events {
+    worker_connections 1024;
+}
+
+stream {
+    server {
+        listen 80;
+
+        proxy_pass 127.0.0.1:8080;
+    }
+
+    server {
+        listen 443 ssl;
+
+        ssl_certificate /etc/nginx/ssl/cert.pem;
+        ssl_certificate_key /etc/nginx/ssl/key.pem;
+
+        proxy_pass 127.0.0.1:8080;
+    }
+}
+
+```
+
+Restart your nginx service
+
+```sh
+sudo systemctl restart nginx
+```
+
+## Ensure the ohttp-relay runs persistently
+
+We can use some built-in flags in docker to run our ohttp-relay in the background.
+
+```sh
+sudo docker run -d --restart unless-stopped --name ohttp-relay -p 8080:8080 \
+    -e PORT=8080 \
+    -e GATEWAY_ORIGIN='https://your-upstream-gateway.com' \
+    your-dockerhub-username/ohttp-relay
+```
+
+the `-d` flag ensures that our container will be running in the background and `--restart unless stopped` will ensure persistence even after logging and server reboots.
+
+That's all it takes to setup an ohttp-relay. The looping allows a sender to send a proposal and receive a Payjoin in an asynchronous way. When you run this program you will participate in coordinating payjoins by relaying data between senders and receivers without .
+
+Check your work by running the curl request below to do a quick check to make sure your server is receiving well.
+
+```sh
+curl -vk --request POST https://35.87.199.174 -H "Content-Type: application/json" --data '{//figure out a good request body for testing//}'
+```