Fix and beautify link to Docker --init

* The content has moved and is apparently now there (old link did not work):
* I use a link text instead of a plain link.

Signed-off-by: rugk <rugk+git@posteo.de>

readme.md

@@ -103,7 +103,7 @@ The following instructions are meant for installations without a web server or r
     <summary>Explanation of the command</summary>
 
     - `sudo docker run` This command spins up a new docker container. Docker commands can optionally be used without `sudo` if the user is added to the docker group (this is not the same as docker rootless, see FAQ below).
-    - `--init` This option makes sure that no zombie-processes are created, ever. See https://docs.docker.com/engine/reference/run/#specify-an-init-process
+    - `--init` This option makes sure that no zombie-processes are created, ever. See [the Docker documentation](https://docs.docker.com/reference/cli/docker/container/run/#init).
     - `--sig-proxy=false` This option allows to exit the container shell that gets attached automatically when using `docker run` by using `[CTRL] + [C]` without shutting down the container.
     - `--name nextcloud-aio-mastercontainer` This is the name of the container. This line is not allowed to be changed, since mastercontainer updates would fail.
     - `--restart always` This is the "restart policy". `always` means that the container should always get started with the Docker daemon. See the Docker documentation for further detail about restart policies: https://docs.docker.com/config/containers/start-containers-automatically/