docs: fix donut paste on win tutorial

Author: jaromil

docs/tutorial.md

@@ -110,7 +110,7 @@ Create the `donut.c` file using the artful code below:
 #### MS/Windows
 
 ```c
-    @"
+@"
                  i,j,k,x,y,o,N;
              main(){float z[1760],a
           #define R(t,x,y) f=x;x-=t*y\
@@ -131,7 +131,7 @@ Create the `donut.c` file using the artful code below:
             " donut.c! \x1b[23A"));}}
               /*no math lib needed
                  .@a1k0n 2021.*/
-    "@| Out-File -FilePath "donut.c" -Encoding ASCII
+"@| Out-File -FilePath "donut.c" -Encoding ASCII
 ```
 
 #### GNU/Linux & Apple/OSX