Update README with Specific File Requirements and Enhance Conda Environments

[benjamin-swain]

Included in this PR:

• Adds a list of the required NSD dataset files in README. The full NSD dataset is ~8.3 TB so this helps save time.
• Adds all required python packages for running all steps (except Reconstruction with Decoded Text Prompt + GAN + Decoded Depth) to the conda env at codes\diffusion_sd1\stable-diffusion\environment.yaml and updates the README with this info.
• Renames the ldm conda env at codes\diffusion_sd2\stable-diffusion\environment.yaml to ldm2 so that the other ldm conda env doesn't have to be removed before creating this one
• Fixes a typo in README where img2feat_sd1.py should be img2feat_sd.py (the other file doesn't exist)

[r1Way]

hello！I have followed your step " Navigate to codes/diffusion_sd1/stable-diffusion/ and run the command conda env create -f environment.yaml". I found that in environment.yaml ,numpy=1.19.2 and pandas==2.0.3 . But in https://pandas.pydata.org/pandas-docs/version/2.0/getting_started/install.html，it is said that the Minimum supported version of NumPy is 1.20.3. How did you solve this problem?