added readme to data folder (#241)

Co-authored-by: Joshua Lampert <51029046+JoshuaLampert@users.noreply.github.com>

Author: cwittens

data/README.md

@@ -0,0 +1,51 @@
+# Experimental Data
+
+This directory contains experimental datasets used in common benchmark problems in dispersive wave modeling. Each dataset has a corresponding function that returns the data as Julia objects for easy integration with DispersiveShallowWater.jl simulations.
+
+## Available Datasets
+
+### Dingemans Experiment Data (`Dingemans.csv`)
+
+The Dingemans experiment is a classic benchmark for validating dispersive shallow water models. It features waves propagating over a trapezoidal bathymetry profile, providing experimental data for wave transformation over varying bottom topography.
+
+The data are taken from the experiments of Maarten Dingemans:
+
+```bibtex
+@techreport{dingemans1994comparison,
+  title={Comparison of computations with {B}oussinesq-like models and laboratory measurements},
+  author={Maarten W. Dingemans},
+  institution={Delft Hydraulics},
+  year={1994},
+  number={H1684.12},
+  url={http://resolver.tudelft.nl/uuid:c2091d53-f455-48af-a84b-ac86680455e9}
+}
+
+@book{dingemans1997water,
+  title={Water Wave Propagation Over Uneven Bottoms},
+  author={Maarten W. Dingemans},
+  year={1997},
+  volume={13},
+  doi={10.1142/1241},
+  publisher={World Scientific}
+}
+```
+
+
+#### Data Format
+
+The CSV file contains time series data with the first column being time values and subsequent columns representing wave height measurements at different spatial locations (six wave gauges).
+
+#### Usage
+
+In order to access the data, execute:
+
+```julia
+t_values, x_values, experimental_data = data_dingemans()
+```
+
+The function returns:
+- `t_values`: Time values at which measurements were recorded
+- `x_values`: Spatial coordinates of the six wave gauges (3.04, 9.44, 20.04, 26.04, 30.44, 37.04)
+- `experimental_data`: Matrix of wave heights at each gauge location (columns) over time (rows)
+
+For more details about this experiment and its use in validation, see the [Dingemans Experiment](https://numericalmathematics.github.io/DispersiveShallowWater.jl/stable/dingemans/) section in the documentation.

src/experimental_data.jl

@@ -10,6 +10,9 @@ and experimental data, which is a matrix of wave heights at each gauge location
 - Dingemans (1997):
   Water Wave Propagation Over Uneven Bottoms (In 2 Parts).
   [DOI: 10.1142/1241](https://doi.org/10.1142/1241)
+
+See also: [Dingemans Experiment](https://numericalmathematics.github.io/DispersiveShallowWater.jl/stable/dingemans/) 
+in the documentation for more details about this experiment and its use in validation.
 """
 function data_dingemans()
     path_dingemans = joinpath(data_dir(), "Dingemans.csv")