Turned the repo into a Cargo workspace, with r701 as a member

Moving the library into its own r701/ directory makes room for the
Tauri GUI client (Oxibadge) to be added as a sibling workspace member
in a following commit. edition/license/repository are now inherited
from the new workspace root instead of being duplicated per member.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Cargo.toml

@@ -1,28 +1,8 @@
-[package]
-name = "r701"
-version = "0.2.0"
+[workspace]
+resolver = "3"
+members = ["r701"]
+
+[workspace.package]
 edition = "2021"
 license = "AGPL-3.0-or-later"
 repository = "https://git.nicolabelluti.me/nicolabelluti/r701"
-
-[dependencies]
-async-stream = "0.3.6"
-chrono = { version = "0.4.38", default-features = false, features = ["clock"] }
-serde = { version = "1.0.203", default-features = false, features = ["derive"],  optional = true }
-tokio = { version = "1.53.1", default-features = false, features = ["net", "io-util", "sync"] }
-tokio-stream = { version = "0.1.19", default-features = false }
-
-[features]
-serde = ["chrono/serde", "dep:serde"]
-
-[lints.rust]
-unsafe_code = "forbid"
-
-[lints.clippy]
-unwrap_used = "deny"
-enum_glob_use = { level = "deny", priority = 1 }
-pedantic = { level = "deny", priority = -1 }
-nursery = { level = "deny", priority = -1 }
-
-[dev-dependencies]
-tokio = { version = "1.53.1", features = ["rt", "macros", "net"] }