Add requirements to readme

Author: prusnak

README.md

@@ -155,7 +155,14 @@ python3 convert-pth-to-ggml.py models/7B/ 1
 
 When running the larger models, make sure you have enough disk space to store all the intermediate files.
 
-TODO: add model disk/mem requirements
+### Requirements
+
+| model | original download size | quantized size (4-bit) |
+|-------|------------------------|------------------------|
+| 7B    | 13 GB                  | 3.9 GB                 |
+| 15B   | 24 GB                  | 7.8 GB                 |
+| 30B   | 60 GB                  | 19.5 GB                |
+| 65B   | 120 GB                 | 38.5 GB                |
 
 ### Interactive mode