Update documentation templates and improve GitHub Actions workflow

Author: petercorke

.github/workflows/main-doc.yml

@@ -15,12 +15,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Set up Python 3.9
-      uses: actions/setup-python@v1
+      uses: actions/setup-python@v5
       with:
         python-version: 3.9
     - name: Checkout main branch
       # checkout mvtb repo into workspace
-      uses: actions/checkout@v2
+      uses: actions/checkout@4
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip

docs/source/_templates/mvtbtemplate.rst

@@ -1,4 +1,4 @@
-{{ fullname | escape | underline}}
+{{ objname | escape | underline}}
 
 .. currentmodule:: {{ module }}
 

docs/source/high-level.rst

@@ -2,7 +2,7 @@
 Class reference
 ***************
 
-These functions deal with images as Python classes.
+A number of Python classes are provided to represent images, image sources, cameras, and point clouds.  These are described in the following sections.
 
 .. toctree::
    :maxdepth: 2