Detect fish configuration

README.md

@@ -25,6 +25,7 @@ Just invoke `topgrade`. It will invoke the following steps:
   * ~/.zshrc
   * [~/.oh-my-zsh](https://github.com/robbyrussell/oh-my-zsh)
   * ~/.tmux
+  * ~/.config/fish/config.fish
 * *Unix*: Invoke [zplug](https://github.com/zplug/zplug) update
 * *Unix*: Upgrade tmux plugins with [TPM](https://github.com/tmux-plugins/tpm)
 * Invoke Cargo [install-update](https://github.com/nabijaczleweli/cargo-update)

src/main.rs

@@ -127,6 +127,7 @@ fn run() -> Result<(), Error> {
         git_repos.insert(home_path(".zshrc"));
         git_repos.insert(home_path(".oh-my-zsh"));
         git_repos.insert(home_path(".tmux"));
+        git_repos.insert(home_path(".config/fish/config.fish"));
     }
 
     if let Some(custom_git_repos) = config.git_repos() {