Pull user visible messages from localization library

Cargo.toml

@@ -16,12 +16,18 @@ diesel = { version = "2.0.2", features = ["chrono", "sqlite"] }
 diesel_migrations = "2.0.0"
 ical = { version = "0.7.0", features = ["ical"], default-features = false }
 log = "0.4.17"
+once_cell = "1.17.0"
 pretty_env_logger = "0.4.0"
 regex = "1.6.0"
 reqwest = "0.11.12"
 rrule = "0.10.0"
+rust-i18n = "1.1.1"
 serde = { version = "1.0.145", features = ["derive"] }
 serde_yaml = "0.9.13"
 teloxide = { version = "0.11.0", features = ["macros", "throttle"] }
 thiserror = "1.0.37"
 tokio = { version = "1.21.2", features = ["macros"] }
+
+[package.metadata.i18n]
+available-locales = ["en", "de"]
+default-locale = "de"