feat: add metadata

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/post3-sdk/Cargo.toml

@@ -2,6 +2,15 @@
 name = "post3-sdk"
 version.workspace = true
 edition.workspace = true
+authors.workspace = true
+license.workspace = true
+repository.workspace = true
+homepage.workspace = true
+rust-version.workspace = true
+description = "Ergonomic Rust SDK for post3 S3-compatible object storage — wraps aws-sdk-s3 with sane defaults"
+keywords = ["s3", "sdk", "client", "object-storage", "aws"]
+categories = ["api-bindings", "web-programming::http-client"]
+readme = "../../README.md"
 
 [dependencies]
 aws-sdk-s3 = "1"