Create a device catalogue

As more groups across DLS are starting to use dodal, it will be very useful to have an organised list of all the common devices, along with a simple description of how that device is used in a beamline (from a hardware perspective).

Once a few of these have been written, I think we should start to ask that PR's adding new devices must also come with a new catalogue entry (open to discussion on this part)

We should create sub-issues to add individual devices to the catalogue

## Acceptance Criteria
- Device catalogue created, containing entries for the most commonly-used devices
- Document that when adding a new device, you should also add an entry to the device catalogue