Update README.md

Author: fritzwill

README.md

@@ -3,6 +3,7 @@ Utilizing root solving techniques such as:
 * Bisection Method
 * Fixed-Point Method
 * Newton's Method
+* Secant Method
 
 Demonstrates numerical methods used to find solutions of nonlinear equations. Each script has a nonlinear function and error tolerance built into it, but both can be changed by the user.