Fix tbzd, update README.md

Author: vaeth

README.md

@@ -2,7 +2,7 @@
 
 A collection of POSIX shell scripts to invoke archiver programs
 
-           (s)tar/gzip/bzip2/xz/zip/7z/lzma/lrzip/arj/zoo/brotli/zopfli/zstd
+    (s)tar/gzip/bzip2/bzip3/xz/zip/7z/lzma/lrzip/arj/zoo/brotli/zopfli/zstd
 
 Author: Martin Väth <martin at mvath.de>
 
@@ -16,6 +16,7 @@ various archiver programs like
 - __zstd__
 - __gzip__/__zopfli__
 - __bzip2__
+- __bzip3__
 - __xz__/__lzma__
 - __zip__
 - __7z__

bin/tgzd

@@ -213,7 +213,7 @@ else	! $xattr || ! $tar_knows_xattr || Push taropts '--xattrs'
 	B)	OptExternal brotlibest
 		Push taropts '--use-compress-program' "$brotlibest";;
 	b)	OptExternal bzipbest
-		Push taropts '--use-compress-program' "$bzip3best";;
+		Push taropts '--use-compress-program' "$bzipbest";;
 	3)	OptExternal bzip3best
 		Push taropts '--use-compress-program' "$bzip3best";;
 	z)	OptExternal zstdbest