For discussion: Update video-miners section in preparation for the merge

[chrishobcroft]

Currently the /video-miners section of the docs is pitched in terms of helping GPU operators "increase profits by transcoding video on GPUs while mining". This implies that you need to be mining, and might evem put off operators who don't wish to engage in PoW, as it isn't immediately clear that you can transcoded without also mining.

AFAIK there are not so many Os who also mine, plus the economics may even work without hashing at the same time as transcoding. Thus, it feels like this section needs a refresh.

Factor in the upcoming switch-off of PoW on Ethereum, GPU operators are going to be looking for ways to re-purpose their hardware.

Clearly, Ethereum isn't the only network that needs hashing, but there is perhaps an opportunity to expand on the green credentials, e.g. "using GPUs for their intended purpose i.e. processing graphics (what a radical concept /s)" instead of "proof-of-waste".

Discuss?