isbin-verifier: add EOF newline (#1616)

Teo-ShaoWei · yawpitch · commit bd68e1be845b · 2019-11-05T11:53:25.000Z
This fix the issue that `configlet generate .` is not idempotent as the track's README might manually adjust for the newline instead. This is something I came across while working on exercism/julia#161.
diff --git a/exercises/isbn-verifier/description.md b/exercises/isbn-verifier/description.md
@@ -37,4 +37,4 @@ Now, it's even trickier since the check digit of an ISBN-10 may be 'X' (represen
 
 * Generate a valid ISBN-13 from the input ISBN-10 (and maybe verify it again with a derived verifier).
 
-* Generate valid ISBN, maybe even from a given starting ISBN.
+* Generate valid ISBN, maybe even from a given starting ISBN.

Original file line number	Diff line number	Diff line change
`@@ -37,4 +37,4 @@ Now, it's even trickier since the check digit of an ISBN-10 may be 'X' (represen`
`37`	`37`
`38`	`38`	`* Generate a valid ISBN-13 from the input ISBN-10 (and maybe verify it again with a derived verifier).`
`39`	`39`
`40`		`-* Generate valid ISBN, maybe even from a given starting ISBN.`
	`40`	`+* Generate valid ISBN, maybe even from a given starting ISBN.`