small note on table to z-table conversion

README.md

@@ -33,6 +33,8 @@ Extracted decision matrix:
 | driving | 3:4 | -4:3 | 3:3 | 3:4 | 3:3 |
 | weight | 5:5 | 3:4 | 4:4 | 1:5 | 5:5 |
 
+> NOTE: Each cell contains `a:b` indicating a fuzzy rating `a` with confidence level `b`. Every number (`a` and `b`) is on a scale from 1 to 5 and is mapped to predefined z-number A and B fuzzy sets.
+
 Ranking (TOPSIS):
 
 ```