For the past few weeks I have noticed some shaking in the steering wheel. I did not know what to make of it.

Yesterday I happened to leave the car parked in such a way that the steering wheel was turned fully to the left, which exposed the inside of the left front tyre to my view.

I was shocked to see that the inside edge of the left front tyre was worn down to the steel belts, while the other two thirds of the tyre had at least 1/8 inch tread on it. After seeing that, I jacked the car up in the front and shook the tyre left and right and top to bottom. There was no play at all.

Does anyone know what problem this may be and how to fix it.

simple fix get your TRACKING checked.

Yes get tracking sorted but that won't cure the shakes, so you may also need the tyres balanced if this doesn't cure the shaking steering then get the front suspension/steering arms/bushes checked.