Parametric Planter Model in OpenSCAD

I need a clean, fully-parametric planter modeled in OpenSCAD. The goal is to receive a single .scad file where every key dimension—overall footprint, height, wall thickness, bottom slope, rim style, drainage-hole pattern—can be tweaked from the top of the script without touching the core geometry.

Please organise the code into logical modules, comment it clearly, and keep dependencies to the standard OpenSCAD library only. The file must render without warnings in the current stable release and export to an error-free STL.

Deliverables
• The annotated .scad source, ready for remixing
• One sample STL generated from default parameters
• A brief read-me (markdown or plain text) explaining each user-editable variable and any printing tips

I’ll test by adjusting values, regenerating the STL, and confirming that walls remain watertight and manifold. If you’ve built similar parametric projects before, feel free to share screenshots or a short clip of the OpenSCAD preview to help me gauge your approach.