Add Documentation 3 (#353)

Add documentation that covers:

- Architecture
- Optimization (only empty template)
- Integration.

Add some PNG figures for architecture documentation including open document
format sources to enable document maintainance.

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>

docs/akkudoktoreos/integration.md

@@ -0,0 +1,34 @@
+% SPDX-License-Identifier: Apache-2.0
+
+# Integration
+
+EOS operates as a [REST](https://en.wikipedia.org/wiki/REST) [API](https://restfulapi.net/) server,
+allowing for seamless integration with a wide range of home automation systems.
+
+## EOSdash
+
+`EOSdash` is a lightweight support dashboard for EOS. It is pre-integrated with EOS. When enabled,
+it can be accessed by navigating to [http://localhost:8503](http://localhost:8503) in your browser.
+
+## Node-RED
+
+[Node-RED](https://nodered.org/) is a programming tool designed for connecting hardware devices,
+APIs, and online services in creative and practical ways.
+
+Andreas Schmitz uses [Node-RED](https://nodered.org/) as part of his home automation setup.
+
+### Resources
+
+- [Installation Guide (German)](https://meintechblog.de/2024/09/05/andreas-schmitz-joerg-installiert-mein-energieoptimierungssystem/) — A detailed guide on integrating an early version of EOS with
+  `Node-RED`.
+
+## Home Assistant
+
+[Home Assistant](https://www.home-assistant.io/) is an open-source home automation platform that
+emphasizes local control and user privacy.
+
+### Resources
+
+- Duetting's [EOS Home Assistant Addon](https://github.com/Duetting/ha_eos_addon) — Additional
+  details can be found in this
+  [discussion thread](https://github.com/Akkudoktor-EOS/EOS/discussions/294).