chore: move audit (paradigmxyz#8922)

README.md

@@ -42,7 +42,7 @@ Reth is production ready, and suitable for usage in mission-critical environment
 
 More historical context below:
 * We released 1.0 "production-ready" stable Reth in June 2024.
-    * Reth completed an audit with [Sigma Prime](https://sigmaprime.io/), the developers of [Lighthouse](https://github.com/sigp/lighthouse), the Rust Consensus Layer implementation. Find it [here](./Sigma_Prime_Paradigm_Reth_Security_Assessment_Report_v1_0.pdf).
+    * Reth completed an audit with [Sigma Prime](https://sigmaprime.io/), the developers of [Lighthouse](https://github.com/sigp/lighthouse), the Rust Consensus Layer implementation. Find it [here](./audit/sigma_prime_audit_v1.pdf).
     * Revm (the EVM used in Reth) underwent an audit with [Guido Vranken](https://twitter.com/guidovranken) (#1 [Ethereum Bug Bounty](https://ethereum.org/en/bug-bounty)). We will publish the results soon.
 * We released multiple iterative beta versions, up to [beta.9](https://github.com/paradigmxyz/reth/releases/tag/v0.2.0-beta.9) on Monday June 3rd 2024 the last beta release.
 * We released [beta](https://github.com/paradigmxyz/reth/releases/tag/v0.2.0-beta.1) on Monday March 4th 2024, our first breaking change to the database model, providing faster query speed, smaller database footprint, and allowing "history" to be mounted on separate drives.