Update NEWS, added announcement for package maintainers
* img2sixel: Marks -D option (read source images from stdin continuously) as deprecated
* Some bug fixes and minor improvements.
- Thanks to @ttdoda.
+ Thanks to @set135, @ttdoda.
+
+* Announcement for package maintainers:
+ Immutable tarball is provided, because GitHub auto-generated tarball may be not immutable.
+
+ https://github.com/saitoha/libsixel/releases/download/v1.8.0/libsixel-1.8.0.tar.gz
+
+ For details, see https://github.com/saitoha/libsixel/issues/64 .
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