[SDXL] Improve docs (#4196)
* Improve docs
* Correct docs
* Add better example inpaint
* make style
* Apply suggestions from code review
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
* fix
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Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
