Json configuration (#141)

* Add json config
* Adjust code to new config

---------

Co-authored-by: Chris <git@nootch.de>

README.md

@@ -9,10 +9,29 @@ See [CONTRIBUTING.md](CONTRIBUTING.md).
 ## Installation
 
 Good installation guide:
-https://meintechblog.de/2024/09/05/andreas-schmitz-joerg-installiert-mein-energieoptimierungssystem/
+<https://meintechblog.de/2024/09/05/andreas-schmitz-joerg-installiert-mein-energieoptimierungssystem/>
 
 The project requires Python 3.10 or newer.
 
+## Configuration
+
+This project uses a `config.json` file to manage configuration settings.
+
+### Default Configuration
+
+A default configuration file `default.config.json` is provided. This file contains all the necessary configuration keys with their default values.
+
+### Custom Configuration
+
+Users can specify a custom configuration directory by setting the environment variable `EOS_DIR`.
+
+- If the directory specified by `EOS_DIR` contains an existing `config.json` file, the application will use this configuration file.
+- If the `config.json` file does not exist in the specified directory, the `default.config.json` file will be copied to the directory as `config.json`.
+
+### Configuration Updates
+
+If the configuration keys in the `config.json` file are missing or different from those in `default.config.json`, they will be automatically updated to match the default settings, ensuring that all required keys are present.
+
 ### Quick Start Guide
 
 On Linux (Ubuntu/Debian):
@@ -27,8 +46,7 @@ On MacOS (requires [Homebrew](https://brew.sh)):
 brew install make
 ```
 
-Next, adjust `config.py`.
-The server can then be started with `make run`. A full overview of the main shortcuts is given by `make help`.
+The server can be started with `make run`. A full overview of the main shortcuts is given by `make help`.
 
 ### Detailed Instructions
 
@@ -65,7 +83,6 @@ source .venv/bin/activate
 
 ## Usage
 
-Adjust `config.py`.
 To use the system, run `flask_server.py`, which starts the server:
 
 ```bash