Clarify readme example, remove depreciated syntax

Author: rafaqz

README.md

@@ -17,8 +17,10 @@ face = FTFont("hack_regular.ttf")
 img, metric = renderface(face, 'C')
 
 # render a string into an existing matrix
-myarray = zeros(UInt8,100,100)
-renderstring!(myarray, "hello", face, (10,10), 90, 10, halign=:hright)
+myarray = zeros(UInt8, 100, 100)
+fontsize = 10
+x0, y0 = 90, 10
+renderstring!(myarray, "hello", face, fontsize, x0, y0, halign=:hright)
 ```
 
 credits to @aaalexandrov from whom most of the early code comes.