feat: Clarifications in README

Extended the README to include a new section on bot configuration setup, emphasizing the necessity of a config.ini file for operation. This update clarifies the setup process for new users, ensuring they understand the requirement of configuring the bot before use. Additionally, outlined the repository policy regarding the use of the `main` branch for development and the process for contributing through feature branches and pull requests, aiming to streamline contribution workflows and maintain code quality.

The formatting improvements across the README enhance readability and ensure consistency in documentation presentation.

README.md

@@ -8,7 +8,7 @@ messages in a Matrix room.
 ## Features
 
 - AI-generated responses to text, image and voice messages in a Matrix room
-(chatbot)
+  (chatbot)
   - Currently supports OpenAI (`gpt-3.5-turbo` and `gpt-4`, including vision
     preview, `whisper` and `tts`)
   - Able to generate pictures using OpenAI `dall-e-2`/`dall-e-3` models
@@ -50,6 +50,11 @@ for all available features.
 You can also use `pip install git+https://git.private.coffee/privatecoffee/matrix-gptbot.git`
 to install the latest version from the Git repository.
 
+#### Configuration
+
+The bot requires a configuration file to be present in the working directory.
+Copy the provided `config.dist.ini` to `config.ini` and edit it to your needs.
+
 #### End-to-end encryption
 
 WARNING: Using end-to-end encryption seems to sometimes cause problems with
@@ -81,31 +86,32 @@ Clone the repository and install the requirements to a virtual environment.
 
 ```shell
 # Clone the repository
-
 git clone https://git.private.coffee/privatecoffee/matrix-gptbot.git
 cd matrix-gptbot
 
 # If desired, activate a venv first
-
 python -m venv venv
 . venv/bin/activate
 
 # Install the bot in editable mode
-
 pip install -e .[dev]
 
 # Go to the bot directory and start working
-
 cd src/gptbot
 ```
 
 Of course, you can also fork the repository on [GitHub](https://github.com/kumitterer/matrix-gptbot/)
 and work on your own copy.
 
-### Configuration
+#### Repository policy
 
-The bot requires a configuration file to be present in the working directory.
-Copy the provided `config.dist.ini` to `config.ini` and edit it to your needs.
+Generally, the `main` branch is considered unstable and should not be used in
+production. Instead, use the latest release tag. The `main` branch is used for
+development and may contain breaking changes at any time.
+
+For development, a feature branch should be created from `main` and merged back
+into `main` with a pull request. The pull request will be reviewed and tested
+before merging.
 
 ## Running