Expand instructions to cover Kate 5.x.

Author: eikehein

README.md

@@ -1,12 +1,21 @@
-To install this theme run:
+To install this highlighting file run:
 
 ```
+# Clone
 git clone https://github.com/rust-lang/kate-config.git`
+
+# The following differs between Kate 4.x and 5.x, see below:
+
+# For Kate 4.x:
 mkdir --parents ~/.kde/share/apps/katepart/syntax
 cp kate-config/rust.xml ~/.kde/share/apps/katepart/syntax
+
+# For Kate 5.x:
+mkdir --parents ~/.local/share/apps/katepart5/syntax
+cp kate-config/rust.xml ~/.local/share/apps/katepart5/syntax
 ```
 
-Then from kate, open a rust file. If rust highlighting
+Then from Kate, open a Rust file. If Rust highlighting
 isn't enabled, enable this setting in the menus:
 
 Tools -> Highlighting -> Sources -> Rust