Update doc/specs/stdlib_quadrature.md

Co-authored-by: Sebastian Ehlert <28669218+awvwgk@users.noreply.github.com>

Author: hsnyder

doc/specs/stdlib_quadrature.md

@@ -270,7 +270,7 @@ If not specified, the default integral is -1 to 1.
 ```fortran
 program integrate
 	use iso_fortran_env, dp => real64
-	implict none
+	implicit none
 
 	integer, parameter :: N = 6
 	real(dp), dimension(N) :: x,w