We have index pages for most modules now, which link to individual classes. It is helpful if these empty class headers are hyperlinks. This commit does just that.
For most sensors/devices so far this is not really necessary as the images are already hyperlinks. But this will become more useful as we start adding index pages like these for classes without images, such as parameters.
Now that each hub is on its own page, we no longer need to collapse snippets to reduce page size. Now they can just all be at the bottom of the page. This also gives each a dedicated link which is easier when giving support.
We were hiding this under a toggle menu to reduce the page size of the hubs module. Now that each hub is on its own page, this is no longer necessary.
In turn, this makes it easier to document the same method for other hubs.
This renames the generic class from LightGrid to LightMatrix. The instance object is simply called display.
This makes user scripts easier to type and read.
This also cleans up most of the draft docstrings for this class and fixes a few argument typos.