Add attribution section for PDAL in documentation

The new section acknowledges the use of PDAL for IO operations in the library, crediting its significant role in simplifying the calculation of forest structural metrics. Citations for the relevant PDAL publications are included to enhance the documentation's scholarly robustness.

docs/index.md

@@ -27,3 +27,11 @@ PyForestScan is a Python library designed for analyzing and visualizing forest s
 - [Getting Started: DTM and CHM](examples/getting-started.ipynb)
 - [Calculating Forest Metrics](examples/calculate-forest-metrics.ipynb)
 - [Working with Large Point Clouds](examples/working-with-large-point-clouds.ipynb)
+
+## Attribution
+
+This library makes heavy use of PDAL (Butler et al. 2024; Butler et al. 2021) for its IO operations. PDAL and the PDAL Python Bindings provide excellent functional support for conducting standard operations on point clouds. Our work to calculate forest structural metrics would have been a lot harder without PDAL. 
+
+Butler, H., Bell, A., Gerlek, M. P., chambbj, Gadomski, P., Manning, C., Łoskot, M., Couwenberg, B., Barker, N., Ramsey, P., Dark, J., Mann, K., Chaulet, N., Rouault, E., Villemin, G., Foster, C., Moore, O., Rosen, M., Lewis, S., ... Brookes, D. (2024). PDAL/PDAL: 2.8.1 (Version 2.8.1). Zenodo. https://doi.org/10.5281/zenodo.13993879
+
+Butler, H., Chambers, B., Hartzell, P., & Glennie, C. (2021). PDAL: An open source library for the processing and analysis of point clouds. Computers & Geosciences, 148, 104680. https://doi.org/https://doi.org/10.1016/j.cageo.2020.104680