Bump version to 2.6.0 (#104)

This version includes some doc improvements and the new `zip_version_made_by` getter function.

Author: nhz2

Project.toml

@@ -1,7 +1,7 @@
 name = "ZipArchives"
 uuid = "49080126-0e18-4c2a-b176-c102e4b3760c"
 authors = ["nhz2 <[email protected]>"]
-version = "2.6.0-dev"
+version = "2.6.0"
 
 [deps]
 ArgCheck = "dce04be8-c92d-5529-be00-80e4d2c0e197"