Report claim as unmaintained. (#1521)

* Report claim as unmaintained.

* Fix template

Co-authored-by: pinkforest <36498018+pinkforest@users.noreply.github.com>

crates/claim/RUSTSEC-0000-0000.md

@@ -0,0 +1,25 @@
+```toml
+[advisory]
+id = "RUSTSEC-0000-0000"
+package = "claim"
+date = "2022-12-04"
+url = "https://github.com/svartalf/rust-claim/issues/12"
+informational = "unmaintained"
+
+[versions]
+patched = []
+```
+
+# `claim` is Unmaintained
+
+The last release was in February 2021, almost two years ago.
+
+The maintainer has been unresponsive regarding this crate for over a year.
+
+A pending issue with `claim`'s dependencies has made the crate [difficul to use](https://github.com/svartalf/rust-claim/issues/9)
+
+## Possible Alternative(s)
+
+The below list has not been vetted in any way and may or may not contain alternatives;
+
+- [`claims`](https://crates.io/crates/claims), a direct fork of the `claim` crate