FreeCAD | Learn the basics

The next step is to learn the basic tools of FreeCAD for a 'feel' of the software, although there is a question here as to whether a small set of 'learn the basics' tutorials or launching right into 'learning whilst working on a practical project' is better (may warrant a separate issue).

The key for us with this repo will be that this isn't ALL the basics of FreeCAD, it is just the ones ***most relevant to laser cutting*** for now.

Whereas I think that #36 can go into the `readme` _now_ (after approval), this section cannot yet be included as first I plan to review a few videos to get a good feel for freeCAD myself and _then_ go into laser cutting specifics. The list of 'basics' will then get pared down and be able to be included in the `readme`.

Any basics that are _obviously required for laser cutting_ can be added to the `readme` as we go, without having to wait for a full list to be compiled.

## Tasks
+ [ ] Find a couple of good resources on basics
+ [ ] Review these and comment with notes on this issue
+ [ ] Pare basics down to the ones that are actually _used_ for laser cutting as we require them and add to the `readme`