Minor improvements to 1985/applin

Now prints a newline after the output. This is to make the output more
friendly to the user as seeing text like:

    $ ./applin
    Hello, world!$

can be confusing or at least annoying.

Further format fixed README.md.

1985/applin/applin.c

@@ -1 +1 @@
-main(v,c)char**c;{for(v[c++]=strdup("Hello, world!\n");(!!c)[*c]&&(v--||--c&&execlp(*c,*c,c[!!c]+!!c,!c));**c=!c)write(!!*c,*c,!!**c);}
+main(v,c)char**c;{for(v[c++]=strdup("Hello, world!\n\n");(!!c)[*c]&&(v--||--c&&execlp(*c,*c,c[!!c]+!!c,!c));**c=!c)write(!!*c,*c,!!**c);}