Initialize the project

- describe how a local develop environment can be set up
- we use poetry to manage the project
  => add pyproject.toml and poetry.lock files
- add a package for the source code
  => "src" layout structure to ensure that pytest runs the tests
     against a packaged version installed in a virtual environment
     and not the *.py files in the project directory
     (Source: https://hynek.me/articles/testing-packaging/)
- ignore poetry's artifacts in git

README.md

@@ -17,6 +17,34 @@ All contributions become open-source themselves, under the
     [MIT license](https://github.com/webartifex/lalib/blob/main/LICENSE.txt).
 
 
+### Local Develop Environment
+
+In order to play with the `lalib` codebase,
+    you need to set up a develop environment on your own computer.
+
+First, get your own copy of this repository:
+
+`git clone git@github.com:webartifex/lalib.git`
+
+While `lalib` comes without any dependencies
+    except core Python and the standard library for the user,
+    we assume a couple of packages and tools be installed
+    to ensure code quality during development.
+These can be viewed in the
+    [pyproject.toml](https://github.com/webartifex/lalib/blob/main/pyproject.toml) file
+    and are managed with [poetry](https://python-poetry.org/docs/)
+    which needs to be installed as well.
+`poetry` also creates and manages a
+    [virtual environment](https://docs.python.org/3/tutorial/venv.html)
+    with the develop tools,
+    and pins their exact installation versions in the
+    [poetry.lock](https://github.com/webartifex/lalib/blob/main/poetry.lock) file.
+
+To replicate the project maintainer's develop environment, run:
+
+`poetry install`
+
+
 ### Branching Strategy
 
 The branches in this repository follow the