chore: add user guide to README.md

README.md

@@ -1,6 +1,33 @@
 # CppToPlantUML
 A simple script that generates a PlantUML class diagram from a C++ source file
 
+## Installation
+
+1. Install [Python 3.11+](https://www.python.org/downloads/release/python-3117/)
+2. Install [Poetry](https://python-poetry.org/docs/)
+3. Clone the repository.
+```bash
+git clone https://github.com/Makcal/CppToPlantUML.git
+```
+4. Install dependencies.
+```bash
+poetry install --no-root
+```
+
 ## Usage
 
-Read `pyhton src/main.py --help` for more information.
+Produces a PlantUML class diagram from a C++ source file to `out.puml` by default.
+
+```bash
+poetry run python src/main.py <source.cpp>
+```
+
+You can enjoy and download your diagram for example with [PlantText](https://www.planttext.com/).
+
+### Help
+
+Read help for options and more information:
+
+```bash
+poetry run python src/main.py --help
+```