wiki update for the manual installation process

[acceleratorlastorder]

Hi, this doesn't look like a bug so I thought this would be more appropriate here.

It seems there is a warning thrown when launching the webui.py script after using the manual installation process as described here: https://github.com/AUTOMATIC1111/stable-diffusion-webui/wiki/Install-and-Run-on-NVidia-GPUs#manual-installation

The warning:
Warning: k_diffusion not found at path C:\stable-diffusion-webui\repositories\k-diffusion\k_diffusion\sampling.py

it seems this line needs to be changed from
pip install git+https://github.com/crowsonkb/k-diffusion.git --prefer-binary
to
git clone https://github.com/crowsonkb/k-diffusion.git repositories/k-diffusion using this removes the warning

This also follows the current code revision since the line found in launch.py seems to use the repositories folder too:

stable-diffusion-webui/launch.py

Line 202 in 7ba3923

git_clone(k_diffusion_repo, repo_dir('k-diffusion'), "K-diffusion", k_diffusion_commit_hash)

Best regards.