README.md in fontist-1.8.12 vs README.md in fontist-1.8.13

@@ -32,9 +32,21 @@
 
 ```sh
 fontist update
 ```
 
+### Dependencies
+
+Depends on
+[ffi-libarchive-binary](https://github.com/fontist/ffi-libarchive-binary) which
+has the following requirements:
+
+* zlib
+* Expat
+* OpenSSL (for Linux only)
+
+These dependencies are generally present on all systems.
+
 ## Usage
 
 ### Font
 
 The `Fontist::Font` is your go to place to deal with any font using fontist. This