Replace docs/README.md -> steps to build docs (#268)

* Replace docs/README.md -> steps to build docs

* Update README.md

---------

Co-authored-by: Jean Luca Bez <[email protected]>

Author: TheAssembler1

docs/README.md

@@ -0,0 +1,44 @@
+# PDC Documentation
+
+This walks you through setting up a local environment
+for building the PDC project documentation.
+
+---
+
+## Requirements
+
+Ensure the following versions are installed on your system. Other versions
+may also work but have not been tested.
+
+- **Python 3.8.18**
+- **pip 25.0.1**
+- **Doxygen 1.13.2**
+
+You can check the versions with:
+> ```bash
+> python3.8 --version
+> pip --version
+> doxygen --version
+> ```
+
+---
+
+## Setup Instructions
+
+### 1. Clone the repository (if not already)
+```bash
+git clone https://github.com/hpc-io/pdc.git
+cd pdc/docs
+```
+
+### 2. Create Python environment install dependencies
+```bash
+python3.8 -m venv .venv
+source .venv/bin/activate
+pip install -r requirements.txt
+```
+
+### 3. Build the html
+```bash
+python -m sphinx -T -b html -d _build/doctrees -D language=en source html
+```