Update README regarding database/theme paths.

README.md

@@ -63,17 +63,20 @@ pacman -S vivid
 
 Check out the [release page](https://github.com/sharkdp/vivid/releases) for binary builds.
 
-Make sure that you install the contents of the `share/vivid` folder to
-`/usr/share/vivid` or `$HOME/.config/vivid` on POSIX systems and `%APPDATA%\vivid` on Windows systems.
-
 ### Via cargo
 
 If you have Rust 1.31 or higher, you can install `vivid` from source via `cargo`:
 ```
 cargo install vivid
 ```
 
-Make sure to install the assets (database: `$srcdir/config/filetypes.yml` and themes: `$srcdir/themes`) to one of the locations listed in the ["On other distributions" section](#on-other-distributions).
+## Customization
+
+Copy the contents of the `share/vivid` folder in this repository to
+`/usr/share/vivid`, `$HOME/.config/vivid`, or `$XDG_CONFIG_PATH/vivid`
+on POSIX systems, or to `%APPDATA%\vivid` on Windows systems.
+
+You can then start to modify these files or add new themes.
 
 ## License