add release notes for version 33.0.0

Author: baronfel

fcs/RELEASE_NOTES.md

@@ -1,3 +1,18 @@
+#### 33.0.0
+
+Integrate dotnet/fsharp from 48f932cf8 to 085985140. Notable changes include:
+
+    allowing '_' as a self-identifier
+    events for FSI evaluation lifecycle events
+    enhancements to FSI return-values
+    fixed parsing for langversion CLI arguments
+    allow cancellation of FSI interactions
+    ToString fixes for value options
+    Fixes for code generation in autogenerated members for very large records
+    make ranges of member declarations capture the entire member
+    improve error recovery in the parser
+    improve logic for auto-detecting framework assemblies for FSI
+
 #### 32.0.0
 
 * integrate dotnet/fsharp from e1b8537ee to 48f932cf8