docs: Be really clear that token-2022 is still under audit (#4435)

program/README.md

@@ -0,0 +1,13 @@
+# Token program
+
+A token program on the Solana blockchain, usable for fungible and non-fungible tokens.
+
+This program provides an interface and implementation that third parties can
+utilize to create and use their tokens.
+
+Full documentation is available at https://spl.solana.com/token
+
+## Audit
+
+The repository [README](https://github.com/solana-labs/solana-program-library#audits)
+contains information about program audits.