Update readme to reflect current status. (WebAssembly#521)

README.md

@@ -2,18 +2,13 @@
 
 # spec
 
-This repository holds a prototypical reference implementation for WebAssembly,
-which is currently serving as the official specification. Eventually, we expect
-to produce a specification either written in human-readable prose or in a formal
-specification language.
+This repository holds the sources for the WebAssembly draft specification
+(to seed a future
+[WebAssembly Working Group](https://lists.w3.org/Archives/Public/public-new-work/2017Jun/0005.html)),
+a reference implementation, and the official testsuite.
 
-It also holds the WebAssembly testsuite, which tests numerous aspects of
-conformance to the spec.
-
-View the work-in-progress spec at [webassembly.github.io/spec](https://webassembly.github.io/spec/).
-
-At this time, the contents of this repository are under development and known
-to be "incomplet and inkorrect".
+A formatted version of the spec is available here:
+[webassembly.github.io/spec](https://webassembly.github.io/spec/),
 
 Participation is welcome. Discussions about new features, significant semantic
 changes, or any specification change likely to generate substantial discussion