Update README.md

Signed-off-by: Fabiana 🚀  Campanari <113218619+FabianaCampanari@users.noreply.github.com>

Author: FabianaCampanari

README.md

@@ -632,11 +632,11 @@ x_2 = \text{quantity produced of product P2}
 
 #### Each resource has limited availability:
 
-#### ➢ [R1 Constraint]():
+#### ➢ [R1]() Constraint:
 
 ### $2x_1 + 4x_2 \leq 100$
 
-#### ➢ [R2 Constraint]():
+#### ➢ [R2]() Constraint:
 
 ### $3x_1 \leq 90$