Added readme for devs

README.md

@@ -0,0 +1,22 @@
+## Prepare for development
+
+After cloning the repository, run the following commands to set up your development environment:
+
+```bash
+python -m venv .venv
+source .venv/bin/activate
+# On Windows use `.venv\Scripts\activate`
+# On Windows with git bash use `source .venv/Scripts/activate`
+bash install.sh
+```
+
+Install cpl-cli as a development package:
+
+```bash
+pip install -e src/core
+pip install -e src/cli
+# test with:
+cpl v
+```
+
+When using Pycharm, mark all directories under `src/` as "Sources Root" and `exa` to ensure proper module resolution.