flang release notes: drop in-progress warnings; minor cleanups

Author: zmodem

flang/docs/ReleaseNotes.md

@@ -1,10 +1,4 @@
-# Flang 11.0.0 (In-Progress) Release Notes
-
-> **warning**
->
-> These are in-progress notes for the upcoming LLVM 11.0.0 release.
-> Release notes for previous releases can be found on [the Download
-> Page](https://releases.llvm.org/download.html).
+# Flang 11.0.0 Release Notes
 
 ## Introduction
 
@@ -17,18 +11,6 @@ documentation](https://llvm.org/docs/ReleaseNotes.html). All LLVM
 releases may be downloaded from the [LLVM releases web
 site](https://llvm.org/releases/).
 
-Note that if you are reading this file from a Git checkout, this
-document applies to the *next* release, not the current one. To see the
-release notes for a specific release, please see the [releases
-page](https://llvm.org/releases/).
-
-## Known Issues
-
-These are issues that couldn't be fixed before the release. See the bug
-reports for the latest status.
-
- *   ...
-
 ## Introducing Flang
 
 Flang is LLVM's Fortran front end and is new for the LLVM 11 release.