fixup cargo.toml, add license files

prometheus-http-client/Cargo.toml

@@ -1,7 +1,14 @@
 [package]
 name = "prometheus-http-client"
 version = "0.1.0"
+description = "HTTP client for Prometheus query API with optional time-series plotting"
+keywords = ["prometheus", "metrics", "monitoring", "plotting"]
+categories = ["web-programming::http-client"]
+authors.workspace = true
+repository.workspace = true
+license.workspace = true
 edition.workspace = true
+include.workspace = true
 
 [lints]
 workspace = true