Fix documentation issues #41 and #42

Issue #41 - Fix old API documentation links:
- Update quickstart.md to link to internal API docs
- Update 1-Meshes.ipynb API link to internal docs
- Update 2-Variables.ipynb API link to internal docs
- Update presentations/_quarto.yml to use ReadTheDocs URL

Issue #42 - Fix broken image and formatting:
- Fix RelaxingMesh.png path from media/ to ../media/

Closes #41, closes #42

Underworld development team with AI support from Claude Code

Author: lmoresi

docs/beginner/quickstart.md

@@ -16,10 +16,7 @@ In addition to the notebooks in this brief set of examples, there are a number o
 
   - [The Underworld Website / Blog](https://www.underworldcode.org)
 
-  - [The API documentation](https://underworldcode.github.io/underworld3/main_api/underworld3/index.html)
-    (all the modules and functions and their full sets of arguments) is automatically generated from the source code and uses the same rich markdown content as the notebook help text.
-
-  - [The API documentation (development branch)](https://underworldcode.github.io/underworld3/development_api/underworld3/index.html)
+  - [The API documentation](../api/index.md) (all the modules and functions and their full sets of arguments) is automatically generated from the source code. You can also access it via the navigation sidebar.
 
   - The [`underworld3` GitHub repository](https://github.com/underworldcode/underworld3) is the most active development community for the code.
 
@@ -85,7 +82,7 @@ Digging a bit deeper into `underworld3`, there are many capabilities that requir
 
 In [Example 8](tutorials/8-Particle_Swarms.ipynb), we made small variations to the mesh to conform to basal topography. We did not remesh, so we had to be careful to apply a smooth, analytic displacement to every node. For more general free-surface models, we need to calculate a smooth function using the computed boundary motions (e.g, solving a poisson equation with known boundary displacements as boundary conditions). We need to step through time and it is common to stabilize the surface motions through a surface integral term that accounts for the interface displacement during the timestep. The example below shows an `underworld3` forward model with internal loads timestepped close to isostatic equilibrium.
 
-```{figure} media/RelaxingMesh.png
+```{figure} ../media/RelaxingMesh.png
 :width: 50%
 
 Stokes flow driven by buoyancy in an annulus defined by two embedded surfaces within an enveloping disk mesh. The surfaces deform in response to the flow. The embedding medium has a very low viscosity but still acts to damp rotational modes. The outer boundary of the disk can be set to a far-field gravitational potential for whole-Earth relaxation models.

docs/beginner/tutorials/1-Meshes.ipynb

@@ -146,35 +146,7 @@
     },
     "tags": []
    },
-   "source": [
-    "There are other pre-built meshes you can try. This is a cuboid divided into regular tetrahedra:\n",
-    "\n",
-    "```python\n",
-    "mesh_usb = uw.meshing.UnstructuredSimplexBox(\n",
-    "    minCoords = (-1.0, -1.0, -1.0),\n",
-    "    maxCoords = (+1.0, +1.0, +1.0),\n",
-    "    cellSize = 0.2,\n",
-    "    regular=True,\n",
-    "    verbose=False,\n",
-    ")\n",
-    "```\n",
-    "\n",
-    "and this is a two-dimensional annulus mesh\n",
-    "\n",
-    "\n",
-    "```python\n",
-    "mesh_ann = uw.meshing.Annulus(\n",
-    "    radiusOuter=1.0,\n",
-    "    radiusInner=0.547,\n",
-    "    cellSize= 0.5,\n",
-    "    cellSizeOuter=0.033,\n",
-    "    cellSizeInner=0.05,\n",
-    "    verbose=False,\n",
-    ")\n",
-    "```\n",
-    "\n",
-    "The meshing infrastructure for underworld3 is documented here: https://underworldcode.github.io/underworld3/main_api/underworld3/meshing.html"
-   ]
+   "source": "There are other pre-built meshes you can try. This is a cuboid divided into regular tetrahedra:\n\n```python\nmesh_usb = uw.meshing.UnstructuredSimplexBox(\n    minCoords = (-1.0, -1.0, -1.0),\n    maxCoords = (+1.0, +1.0, +1.0),\n    cellSize = 0.2,\n    regular=True,\n    verbose=False,\n)\n```\n\nand this is a two-dimensional annulus mesh\n\n\n```python\nmesh_ann = uw.meshing.Annulus(\n    radiusOuter=1.0,\n    radiusInner=0.547,\n    cellSize= 0.5,\n    cellSizeOuter=0.033,\n    cellSizeInner=0.05,\n    verbose=False,\n)\n```\n\nThe meshing infrastructure for underworld3 is documented in the [API documentation](../../api/meshing.md)."
   },
   {
    "cell_type": "code",

docs/beginner/tutorials/2-Variables.ipynb

@@ -271,11 +271,7 @@
     },
     "tags": []
    },
-   "source": [
-    "## More information\n",
-    "\n",
-    "The meshVariable code is described [**API docs** here.](https://underworldcode.github.io/underworld3/development_api/underworld3/discretisation.html#underworld3.discretisation.MeshVariable)"
-   ]
+   "source": "## More information\n\nThe meshVariable code is described in the [API documentation](../../api/discretisation.md)."
   }
  ],
  "metadata": {

docs/presentations/_quarto.yml

@@ -17,4 +17,4 @@ format:
         href: https://github.com/underworldcode/underworld3
       - text: Documentation
         icon: book
-        href: https://underworldcode.github.io/underworld3/
+        href: https://underworld3.readthedocs.io/