Fix section headers and suggest samtool's hts-specs from upstream as …

…advised in samtools/hts-specs#766

README.md

@@ -1,13 +1,15 @@
-##tiny-test-data
+## tiny-test-data
 Super small biological datasets designed with unit testing in mind.
 
-###rationale
+UPDATE: Probably use [hts-specs](https://github.com/samtools/hts-specs/tree/master/test) test data instead?
+
+### rationale
 Tests are great to have but they are not very fun to write and coming
 up with small datasets for testing, especially given the myriad of
 file formats we deal with, is often super annoying.  One way to make
 tests less not-fun to write is to have a handy set of tiny test data
 at hand.
 
-###contributing
+### contributing
 If you have a nice set of tiny test data of your own please open up a
 pull request.