Show panicking APIs in docs, README on crates.io

Cargo.toml

@@ -7,6 +7,7 @@ exclude = [".github", ".editorconfig", "rustfmt.toml"]
 repository = "https://github.com/time-rs/time"
 keywords = ["date", "time", "calendar", "duration"]
 categories = ["date-and-time"]
+readme = "README.md"
 license = "MIT OR Apache-2.0"
 # TODO Add GitHub Actions badge once rust-lang/crates.io#1838 is merged.
 description = "Date and time library. Fully interoperable with the standard library. Mostly compatible with #![no_std]."
@@ -19,3 +20,6 @@ panicking-api = []
 
 [dependencies]
 serde = { version = "1", optional = true, default-features = false, features = ["derive", "alloc"] }
+
+[package.metadata.docs.rs]
+all-features = true