go/types: updated README

Change-Id: Ib4a86240ca82722d522f8b1ce67c96695c7c4b13

src/go/types/README

@@ -78,7 +78,7 @@ idea how to implement that but we can easily type-check it).
 MAJOR KNOWN ISSUES
 
 - importing of packages exporting generic code is not implemented
-  (and won't be implemented in this prototype)
+  in the type-checker
 - various type-specific operations (such as sending a message, type
   assertions, etc.) on expressions of a generic type don't work yet
   (but are relatively easy to implement going forward)
@@ -94,7 +94,7 @@ current state and issues.
 TO PLAY WITH THIS PROTOTYPE
 
 - Cherry-pick this CL on top of tip (the cherry-pick was tested with
-  tip at cae9a9fd65):
+  tip at 1f231d74f6):
 
   git fetch "https://go.googlesource.com/go" ... && git cherry-pick FETCH_HEAD
 
@@ -138,5 +138,6 @@ Updates:
 12/19/2019: Several bugs around type bounds checking fixed; more complex examples.
 12/20/2019: Treat contracts as objects, not types anymore. Various bug fixes and more examples.
 1/14/2020: Implemented contract embedding and instantiation. Lots of bug fixes.
+3/12/2020: Many bug fixes. First steps towards a source-to-source translator.
 
 Change-Id: I29839b5e95d7050fce1dcb3334d3d324883cf76f