Migrate container docs to main documentation

Signed-off-by: David Mehren <git@herrmehren.de>

docs/content/setup/docker.md

@@ -1,20 +1,105 @@
 # HedgeDoc Docker Image
 
-[![Try in PWD](https://cdn.rawgit.com/play-with-docker/stacks/cff22438/assets/images/button.png)](http://play-with-docker.com?stack=https://github.com/hedgedoc/container/raw/master/docker-compose.yml&stack_name=hedgedoc)
+!!! info "Requirements on your server"
+    - [Git](https://git-scm.com/)
+    - [Docker](https://docs.docker.com/get-docker/) 17.03.1 or higher
+    - [Docker Compose](https://docs.docker.com/compose/install/)
 
-## Debian-based version
+The official docker images are [available on quay.io](https://quay.io/repository/hedgedoc/hedgedoc).
+We currently only support the AMD64 architecture.
 
-[![Docker Repository on Quay](https://quay.io/repository/hedgedoc/hedgedoc/status "Docker Repository on Quay")](https://quay.io/repository/hedgedoc/hedgedoc)
 
-## Alpine-based version
+The easiest way to get started with HedgeDoc and Docker is to use the following `docker-compose.yml`:
 
-[![Docker Repository on Quay](https://quay.io/repository/hedgedoc/hedgedoc/status "Docker Repository on Quay")](https://quay.io/repository/hedgedoc/hedgedoc)
-
-The easiest way to setup HedgeDoc using docker are using the following three commands:
-
-```sh
+```shell
 git clone https://github.com/hedgedoc/container.git hedgedoc-container
 cd hedgedoc-container
 docker-compose up
 ```
-Read more about it in the [container repository](https://github.com/hedgedoc/container).
+HedgeDoc should now be available at http://127.0.0.1:3000.  
+You can configure your container with a config file or with env vars.
+Check out [the configuration docs](/configuration) for more details.
+
+## Upgrading
+
+!!! warning
+    Before you upgrade, **always read the release notes**.  
+    You can find them on our [releases page](https://hedgedoc.org/releases/).
+
+!!! info "Upgrading to 1.7"
+    Together with changing the name to "HedgeDoc" the default username,
+    password and database name have been changed in `docker-compose.yml`.
+
+    In order to migrate the existing database to the new default credentials, run
+    ```shell
+    docker-compose exec database createuser --superuser -Uhackmd postgres
+    docker-compose exec database psql -Upostgres -c "alter role hackmd rename to hedgedoc; alter role hedgedoc with password 'password'; alter database hackmd rename to hedgedoc;"
+    ```
+    before running `docker-compose up`.
+
+You can upgrade to the latest release using these commands:
+
+```shell
+cd hedgedoc-container # Enter the directory you previously cloned into
+git pull # Pull new commits
+docker-compose pull # Pull new container images
+docker-compose up # Start with the new images
+```
+
+### Migrating from HackMD
+
+If you used the [`docker-hackmd`](https://github.com/hackmdio/docker-hackmd) repository before,
+you can migrate to [`hedgedoc-container`](https://github.com/hedgedoc/container).
+
+`hedgedoc-container` is a fork of `docker-hackmd`, so you need to replace the upstream URL:
+
+```shell
+git remote set-url origin https://github.com/hedgedoc/container.git
+git pull
+```
+
+Since both codebases diverged since the fork, we recommend that you read the
+[HedgeDoc release notes](https://hedgedoc.org/releases/) at
+least since 1.6.0 and follow any instructions present there. A particular issue
+that has come up is when handling TLS connections when using a reverse proxy.
+You must [set the `X-Forwarded-Proto` header
+correctly](https://docs.hedgedoc.org/guides/reverse-proxy/).
+
+
+## Backup
+
+If you use a PostgreSQL database, you can leverage this command to create a backup: 
+
+```shell
+ docker-compose exec database pg_dump hedgedoc -U hedgedoc > backup.sql
+```
+
+
+## Restore
+
+If you want to restore your PostgreSQL backup, run these commands before starting the application for the first time:
+
+```shell
+docker-compose up -d database
+cat backup.sql | docker exec -i $(docker-compose ps -q database) psql -U hedgedoc
+```
+
+## Custom build
+
+The default setting is to use pre-built docker images.  
+If you want to build your own containers uncomment the `build` section in the
+[`docker-compose.yml`](https://github.com/hedgedoc/container/blob/master/docker-compose.yml)
+and edit the
+[`config.json`](https://github.com/hedgedoc/container/blob/master/resources/config.json).
+
+If you change the database settings and don't use the `CMD_DB_URL` make sure
+you edit the
+[`.sequelizerc`](https://github.com/hedgedoc/container/blob/master/resources/.sequelizerc).
+
+## Issues
+
+If you have any problems with or questions about this image, please contact us
+through a [GitHub issue](https://github.com/hedgedoc/container/issues).
+
+You can also reach many of the project maintainers via our matrix room
+[`#hedgedoc:matrix.org`](https://chat.hedgedoc.org).