Proofread install_poetry.md (#433)

Include poetry logo

docs/install_poetry.md

+<center>
+![Poetry logo](images/poetry-logo.svg){: style="height:120px;width:120px"}
+</center>
+
 ## Install Silkaj in a development environement with Poetry
 
 ### Install libsodium
 
-```bash
-sudo apt install libsodium23 # Debian Buster
-sudo apt install libsodium18 # Debian Stretch
-sudo dnf install libsodium # Fedora
-```
+=== "Debian"
+    ```
+    sudo apt install libsodium23
+    ```
+
+=== "Fedora"
+    ```
+    sudo dnf install libsodium
+    ```
 
 ### Install Poetry
 
 - [Installation documentation](https://python-poetry.org/docs/#installation)
 
-### On Debian Buster
-
-```bash
-sudo apt install python3-pip python3-venv
-sudo apt install libffi-dev # Required on ARMbian
-pip3 install poetry --user
+```
+pipx install poetry
 ```
 
 ### Install dependencies and the Python virtual environment
@@ -45,17 +49,15 @@ poetry run silkaj
 
 ### Poetry shell
 
-You can access tools (`pytest`, `black`) from within the development environment with `poetry run` or by entering the shell:
+You can access tools `pytest` from within the development environment with `poetry run` or by entering the shell:
 
 ```bash
 silkaj> poetry run pytest
-silkaj> poetry run black
 ```
 
 ```bash
 silkaj> poetry shell
-(silkaj-58dUTebQ-py3.9) silkaj> black
-(silkaj-58dUTebQ-py3.9) silkaj> pytest
+(silkaj-58dUTebQ-py3.12) silkaj> pytest
 ```
 
 ### Make Silkaj accessible from everywhere