Simplify Kroki install procedure

Avoid duplicating a lot of content from the official installation page: https://docs.kroki.io/kroki/setup/install/.

doc/administration/integration/kroki.md

@@ -37,75 +37,8 @@ The **Kroki URL** will be the hostname of the server running the container.
 - [Vega-Lite](https://github.com/vega/vega-lite)
 - [WaveDrom](https://wavedrom.com/)
 
-In other words, the following endpoints will be available:
-
-```plaintext
-/bytefield
-/c4plantuml
-/ditaa
-/erd
-/graphviz
-/dot
-/nomnoml
-/plantuml
-/svgbob
-/umlet
-/vega
-/vegalite
-/wavedrom
-```
-
-If you want to use _ActDiag_, _BlockDiag_, _NwDiag_, _PacketDiag_, _RackDiag_, _SeqDiag_, _Mermaid_ or _BPMN_, then you will also need to start companion containers:
-
-[`yuzutech/kroki-blockdiag`](https://hub.docker.com/r/yuzutech/kroki-blockdiag)
-
-Provides block, sequence, activity and network diagrams for Kroki using respectively
-[ActDiag](http://blockdiag.com/en/actdiag/index.html),
-[BlockDiag](http://blockdiag.com/en/blockdiag/index.html),
-[NwDiag](http://blockdiag.com/en/nwdiag/index.html),
-[PacketDiag](http://blockdiag.com/en/nwdiag/packetdiag-examples.html),
-[RackDiag](http://blockdiag.com/en/nwdiag/rackdiag-examples.html),
-and [SeqDiag](http://blockdiag.com/en/seqdiag/index.html) libraries.
-
-[`yuzutech/kroki-mermaid`](https://hub.docker.com/r/yuzutech/kroki-mermaid)
-
-Provides flowchart, sequence and Gantt diagrams for Kroki using [Mermaid](https://mermaidjs.github.io).
-
-[`yuzutech/kroki-bpmn`](https://hub.docker.com/r/yuzutech/kroki-bpmn)
-
-Provides BPMN diagrams for Kroki using [bpmn-js](https://bpmn.io/toolkit/bpmn-js).
-
-You can use `docker-compose` to run multiple containers.
-Here's an example where we start all the containers using a `docker-compose.yml` file:
-
-```yaml
-version: "3"
-services:
- core:
-   image: yuzutech/kroki
-   environment:
-     - KROKI_BLOCKDIAG_HOST=blockdiag
-     - KROKI_MERMAID_HOST=mermaid
-     - KROKI_BPMN_HOST=bpmn
-   ports:
-     - "8000:8000"
- blockdiag:
-   image: yuzutech/kroki-blockdiag
-   expose:
-     - "8001"
- mermaid:
-   image: yuzutech/kroki-mermaid
-   expose:
-     - "8002"
- bpmn:
-   image: yuzutech/kroki-bpmn
-   expose:
-     - "8003"
-```
-
-```shell
-docker-compose up -d
-```
+If you want to use additional diagram libraries,
+read the [Kroki installation](https://docs.kroki.io/kroki/setup/install/#_images) to learn how to start Kroki companion containers. 
 
 ## GitLab