Describe features

README.md

@@ -6,6 +6,22 @@ SlackBuild meta information accordingly.
 
 ## Features
 
+- Querying various sources (like registries) for the latest upstream version.
+  Currently supported sources are:
+  - GitHub
+  - Packagist
+  - Remote text file containing a version number (like the LATEST file).
+- Updating package version and checksum in the .info file;
+  Updating version variables in the .SlackBuild
+- Updating packages with multiple sources. One source is assumed to be the main
+  source and match the version of the package. Other sources are just updated to
+  the latest version available for them.
+- Modifying or just reuploading source tarballs to a different destination.
+  SlackBuilder can download the original source tarball, optionally extract and
+  modify its contents, and upload it to another server. It can be used for
+  example to download package dependencies to ship them all within a single
+  archive, so the package can be built offline.
+
 ## Build instructions
 
 SlackBuilder is a Haskell program and can be built and run using the