Stable version 0.8.0

This release is dedicated to dibblego, who pushed me down the Haskell
rabbit hole. In 2006 I thought you were crazy. Today I *know* you are.

CHANGELOG.md

-## Git (0.8.0)
+## v0.8.0 - 2021-11-06
 ### Added
 - `disable=all` now conveniently disables all warnings
 - `external-sources=true` directive can be added to .shellcheckrc to make

ShellCheck.cabal

 Name:             ShellCheck
-Version:          0.7.2
+Version:          0.8.0
 Synopsis:         Shell script analysis tool
 License:          GPL-3
 License-file:     LICENSE