build: add package metadata to member crates for publishing

Include descriptions, keywords, categories, and workspace-inherited fields (repository, homepage, readme) to prepare crates for distribution on crates.io.

crates/irtt-client/Cargo.toml

@@ -1,9 +1,15 @@
 [package]
 name = "irtt-client"
 version = "0.1.0"
+description = "IRTT-compatible Rust client library"
 edition.workspace = true
 license.workspace = true
 rust-version.workspace = true
+repository.workspace = true
+homepage.workspace = true
+readme.workspace = true
+keywords = ["irtt", "networking", "latency", "rtt"]
+categories = ["network-programming"]
 
 [dependencies]
 irtt-proto.workspace = true
@@ -14,3 +20,6 @@ thiserror = "2"
 [features]
 default = []
 ancillary = ["dep:libc"]
+
+[package.metadata.docs.rs]
+all-features = true