Add README with tutorial

README.md

+DNS over HTTPS
+===
+
+Running an own DNS over HTTPS (DoH) server seems to be not so common. Even when the technology gets more and more traction. Chromium/-e as well as Firefox have implemented it in their browser and run requests to major DNS providers like Google or Cloudflare.
+
+In order to liberate and democratize the usage of DoH this container image provides the base to run a setup along with any recursive DNS server you like.
+
+The example docker-compose runs along with [secns' unbound](https://hub.docker.com/r/secns/unbound) that provides DNSSec validation.
+
+The project itself is based on [m13253's work](https://github.com/m13253/dns-over-https) providing a DoH-proxy in golang.
+
+Usage
+---
+
+The current example requires you to have a HTTPS reverse-proxy running.
+
+```bash
+git clone https://octo.sh/container-library/dns-over-https.git
+cd dns-over-https
+docker-compose up -d
+```
+
+This will download and setup the mentioned unbound DNS server along with the proxy, which will be exposed on `127.0.0.1:8053`.
+
+To test that it's working run: `curl 'http://127.0.0.1:8053/dns-query?name=shivering-isles.com&type=A'`
+
+Or `curl 'http://127.0.0.1:8053/dns-query?name=shivering-isles.com&type=A' | jq` when you prefer a beautified output.
+
+Setup a reverse proxy that takes care of HTTPS and you can [set it up on your browser](https://support.mozilla.org/en-US/kb/connection-settings-firefox) :tada:

docker-compose.yml

@@ -9,4 +9,4 @@ services:
     environment:
       - "UPSTREAM_NAME=dns"
     ports:
-      - "8053:8053"
+      - "127.0.0.1:8053:8053"