This commit cleans up the code that did bulk imports of legacy model
files. The code has been refactored, and the user is now offered the
option of importing all the model files found in the directory, or
selecting which ones to import.
I found I needed to use double backslashes to import a new model, when using single backslash the output would say "e:_ProjectsCodemodelsldmstable-diffusion-model-to-import.ckpt is neither the path to a .ckpt file nor a diffusers repository id. Can't import." This added tip in the documentation will help Windows users overcome this.
1. Added a big fat warning to the Windows installer to tell user
to install Visual C++ redistributable.
2. Added a bit fat warning to the automated installer doc to
tell user the same thing.
3. Reordered entries on the table-of-contents sidebar for installation
to prioritize the most important docs.
4. Moved older installation documentation into deprecated folder.
5. Moved developer-specific installation documentation into the
developers folder.
