Update the README.md to mention that this is the core testsuite.

sunfishcode · sunfishcode · commit 2375d1eec495 · 2018-02-25T06:37:07.000-08:00
diff --git a/README.md b/README.md
@@ -1,2 +1,2 @@
-This repository holds a mirror of the spec testsuite which is maintained
+This repository holds a mirror of the WebAssembly core testsuite which is maintained
 [here](https://github.com/WebAssembly/spec/tree/master/test/core).

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,2 @@`
`1`		`-This repository holds a mirror of the spec testsuite which is maintained`
	`1`	`+This repository holds a mirror of the WebAssembly core testsuite which is maintained`
`2`	`2`	`[here](https://github.com/WebAssembly/spec/tree/master/test/core).`