Add build instructions [skip ci]

Author: t-sommer

README.md

@@ -12,7 +12,7 @@ A Modelica library to import [Functional Mock-up Units](https://fmi-standard.org
 
 ## Installation
 
-Install the `modelica-fmi` command with [uv](https://docs.astral.sh/uv/getting-started/installation/):
+To import FMUs install the `modelica-fmi` and `modelica-fmi-gui` commands with [uv](https://docs.astral.sh/uv/getting-started/installation/):
 
 ```bash
 uv tool install --reinstall https://github.com/modelica/Modelica-FMI/releases/download/v0.0.6/modelica_fmi-0.0.6-py3-none-any.whl
@@ -24,7 +24,7 @@ Or, with `pip`:
 pip install https://github.com/modelica/Modelica-FMI/releases/download/v0.0.6/modelica_fmi-0.0.6-py3-none-any.whl
 ```
 
-Then download the [Modelica-FMI](https://github.com/modelica/Modelica-FMI/releases/download/v0.0.6/Modelica-FMI-0.0.6.zip) package and load it in your Modelica tool.
+To simulate imported FMUs download the [Modelica-FMI](https://github.com/modelica/Modelica-FMI/releases/download/v0.0.6/Modelica-FMI-0.0.6.zip) package and load it in your Modelica tool.
 
 ## Usage
 
@@ -46,6 +46,48 @@ In Dymola you can open the import dialog by opening the `FMI` package and select
 
 After the import you have to reload the package.
 
+## Building the binaries from source
+
+To build the binaries in `FMI/Resources/Library` from source install CMake
+
+```
+uv tool install cmake
+```
+
+clone the repository, and run
+
+```
+cmake -S runtime -B runtime/build
+```
+
+```
+cmake --build runtime/build --config release --target install
+```
+
+## Building distributable import commands
+
+To build distributable version of the `modelica-fmi` and `modelica-fmi-gui` commands
+
+- create a new virtual environment
+```
+uv venv
+```
+
+- install PyInstaller and modelica_fmi
+```
+uv pip install pyinstaller https://github.com/modelica/Modelica-FMI/releases/download/v0.0.6/modelica_fmi-0.0.6-py3-none-any.whl
+```
+
+- build modelica-fmi-gui
+```
+uv run pyinstaller --windowed --name modelica-fmi-gui --collect-data modelica_fmi .venv/Lib/site-packages/modelica_fmi/gui/__main__.py
+```
+
+- ...or modelica-fmi
+```
+uv run pyinstaller --name modelica-fmi --collect-data modelica_fmi .venv/Lib/site-packages/modelica_fmi/__main__.py
+```
+
 ## License
 
 Copyright © 2025 Modelica Association.