[flutter]: add some scripts

scripts/makefile/env.toml

@@ -39,6 +39,32 @@ cargo install cargo-cache
 cargo install bunyan
 """
 
+[tasks.install_cocoapods]
+script = """
+# execute "xcode-select --install" before if "extconf.rb failed" error occurs
+sudo gem install cocoapods
+"""
+
+[tasks.install_rbenv]
+script = """
+brew install rbenv
+rbenv init
+rbenv install 2.7.1
+rbenv global 2.7.1
+
+# https://github.com/rbenv/rbenv
+curl -fsSL https://github.com/rbenv/rbenv-installer/raw/main/bin/rbenv-doctor | bash
+"""
+
+[tasks.install_fish]
+script = """
+brew install fish
+
+# https://stackoverflow.com/questions/26208231/modifying-path-with-fish-shell
+# Export the PATH using the command:
+# set -Ua fish_user_paths the_path_you_want_to_export
+"""
+
 [tasks.install_flutter]
 script = """
 echo "[❤️] Follow the https://flutter.dev/docs/get-started/install instructions to install the flutter, skip if you already installed."