Better overview page for tutorials (#1093)

* better overview page

* review

Author: svchb

docs/src/tutorial.md

@@ -1,8 +1,55 @@
 # Tutorials
 
-## General
-- [Setting up your simulation from scratch](tutorials/tut_setup.md)
-- [Modifying or extending components of TrixiParticles.jl within a simulation file](tutorials/tut_custom_kernel.md)
+> New to TrixiParticles.jl? Start with [Setting up your simulation from scratch](tutorials/tut_setup.md).
 
-## Preprocessing
-- [Particle packing tutorial](tutorials/tut_packing.md)
+## Recommended Path
+
+1. [Setting up your simulation from scratch](tutorials/tut_setup.md): learn the structure of a simulation file and run a complete WCSPH example.
+2. [Modifying or extending components of TrixiParticles.jl within a simulation file](tutorials/tut_custom_kernel.md): replace selected parts of an existing setup without cloning the package.
+3. [Particle packing tutorial](tutorials/tut_packing.md): build a body-fitted particle configuration for complex geometries.
+
+## Tutorials
+
+### [Setting up your simulation from scratch](tutorials/tut_setup.md)
+
+```@raw html
+<img src="../tutorials/tut_setup_plot_tank.png"
+     alt="Rectangular tank setup used in the first tutorial"
+     style="max-width: 360px; width: 100%; border-radius: 12px;" />
+```
+
+Build a complete Weakly Compressible SPH dam break setup from particle spacing through
+semidiscretization, callbacks, and time integration.
+
+- Focus: initial conditions, systems, semidiscretization, callbacks
+- Choose this if: you want the full workflow for a minimal example
+
+### [Modifying or extending components of TrixiParticles.jl within a simulation file](tutorials/tut_custom_kernel.md)
+
+```@raw html
+<img src="../tutorials/tut_custom_kernel_plot2.png"
+     alt="Kernel comparison plot from the custom kernel tutorial"
+     style="max-width: 360px; width: 100%; border-radius: 12px;" />
+```
+
+Start from an existing simulation and replace pieces such as the smoothing kernel
+directly in the file you run.
+
+- Focus: `trixi_include`, custom kernels, rapid iteration
+- Choose this if: you want to prototype changes without cloning and modifying the package
+
+### [Particle packing tutorial](tutorials/tut_packing.md)
+
+```@raw html
+<img src="https://github.com/user-attachments/assets/0f7aba29-3cf7-4ec1-8c95-841e72fe620d"
+     alt="Packed particle configuration for a complex geometry"
+     style="max-width: 360px; width: 100%; border-radius: 12px;" />
+```
+
+Go from a geometry file to a packed particle distribution using signed distance fields
+together with boundary and interior sampling.
+
+- Focus: geometry import, signed distance fields, boundary sampling, `ParticlePackingSystem`
+- Choose this if: you need body-fitted particles for complex geometries
+
+See also [Getting started](getting_started.md) and [Examples](examples.md).