Add 2015/endoh3/try.sh + format/typo checks

A new make rule (or alias for mullender and back_to) called 'future' was
added for the theme. The try.sh script uses make future ('back_to' just
doesn't look that good in my eyes even when I added it).

The try.sh tries to stay in character with the award theme a bit too
though that will only be noticeable if you pay attention. I found the
films very boring (though maybe years later I would find it more
enjoyable) so I'm sure that something more fun could have been
added if I knew them more but I do not. Well I tried anyway.

thanks-for-help.md

@@ -3818,9 +3818,11 @@ they avoided.
 symbols of `main()`. The fix is through the compiler option `-fcommon` which
 will let it compile like it does with macOS.
 
-Cody also made it easier to enjoy the theme of [Back to the
+Cody also added the [try.sh](2015/endoh3/try.sh) script which makes use of the
+make rule he added (to enjoy the theme of the entry, [Back to the
 Future](https://en.wikipedia.org/wiki/Back_to_the_Future) using this entry by
-simply typing `make back_to` or `make mullender`.
+simply typing `make back_to` or `make mullender`) and then runs the famous
+[1984/mullender.c](/1984/mullender/mullender.c).
 
 
 ## [2015/hou](2015/hou/prog.c) ([README.md](2015/hou/README.md))