feat: add metadata

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

crates/post3-server/Cargo.toml

@@ -2,6 +2,15 @@
 name = "post3-server"
 version.workspace = true
 edition.workspace = true
+authors.workspace = true
+license.workspace = true
+repository.workspace = true
+homepage.workspace = true
+rust-version.workspace = true
+description = "S3-compatible HTTP server with pluggable PostgreSQL and filesystem backends"
+keywords = ["s3", "server", "object-storage", "http", "axum"]
+categories = ["web-programming::http-server", "database", "filesystem"]
+readme = "../../README.md"
 
 [dependencies]
 post3.workspace = true