corrected documentation

Author: aman-godara

doc/specs/stdlib_strings.md

@@ -371,11 +371,11 @@ program demo_replace_all
   implicit none
   type(string_type) :: string
 
-  string = "hurdles here, hurdles there, hurdles everwhere"
-  ! string <-- "hurdles here, hurdles there, hurdles everwhere"
+  string = "hurdles here, hurdles there, hurdles everywhere"
+  ! string <-- "hurdles here, hurdles there, hurdles everywhere"
 
-  print '(a)', replace_all(string, "hurdles", "learn from")
-  ! "learn from here, learn from there, learn from everwhere"
+  print'(a)', replace_all(string, "hurdles", "learn from")
+  ! "learn from here, learn from there, learn from everywhere"
 
   string = replace_all(string, "hurdles", "technology")
   ! string <-- "technology here, technology there, technology everywhere"