Add missing MIDI files to 2020/otterness

These files in particular were previously to be downloaded prior to use
of the program (or try section). These files have now been downloaded
and added to the repo.

Format/typo check README.md file.

Updated bugs.md with features/limitations.

thanks-for-help.md

@@ -4443,6 +4443,15 @@ set by the late Christopher Tolkien, son and literary executor and heir to
 J.R.R. Tolkien).
 
 
+## <a name="2020_otterness"></a>[2020/otterness](/2020/otterness/prog.c) ([README.md](/2020/otterness/README.md))
+
+
+[Cody](#cody) added the MIDI files [cvikl.mid](/2020/otterness/cvikl.mid) and
+[entertainer.mid](/2020/otterness/entertainer.mid) from the URLs we suggested so
+that one need not download them and to make sure they can always be obtained
+even if the domain or link goes dead.
+
+
 ## <a name="2020_tsoj"></a>[2020/tsoj](/2020/tsoj/prog.c) ([README.md](/2020/tsoj/README.md))
 
 [Cody](#cody) added [alternate code](/2020/tsoj/README.md#alternate-code) that will feel