Documentation Updates

[ikeough]

• Point light is too bright.
• Spot light is too bright.
• GridLine needs an example.
• Joist example is blank.
• Material needs an example.
• ModelText example is really small.
• Opening needs an example (maybe wait until after Everything ifc #531)
• StandardWall openings are in the wrong place in the example.
• ParametricProfile could use an example (@ikeough)
• AdaptiveGrid needs an example (@wynged)
• ModelLines example is broken.
• ContentElement needs an example (@wynged)
• ContentCatalog needs an example (@wynged)

[ikeough]

Partially fixed in #773. Awaiting more doc updates.