chore: bb repo warning (#7023)

barretenberg/README.md

@@ -1,10 +1,7 @@
-## Barretenberg, an optimized elliptic curve library for the bn128 curve, and PLONK SNARK prover
-
-Barretenberg aims to be a stand-alone and well-specified library, but please see https://github.com/AztecProtocol/aztec-packages/edit/master/barretenberg for the authoritative source of this code.
-The separate repository https://github.com/AztecProtocol/barretenberg is available if working on barretenberg independently of Aztec, however it is encouraged to develop in the context of Aztec to see if it will cause issues for Aztec end-to-end tests.
-**Currently, merging only occurs in aztec-packages. This is a mirror-only repository until it matures. Legacy release merges need an admin**
-As the spec solidifies, this should be less of an issue. Aztec and Barretenberg are currently under heavy development.
+# :warning: This is not an actively developed repository, it is a mirror. See https://github.com/AztecProtocol/aztec-packages :warning:
+# :warning: **https://github.com/AztecProtocol/barretenberg is a mirror-only repository, please only use https://github.com/AztecProtocol/aztec-packages. Do not use this for any purpose other than reference.** :warning: </span>
 
+## Barretenberg, an optimized elliptic curve library for the bn128 curve, and PLONK SNARK prover
 **This code is highly experimental, use at your own risk!**
 
 ### Benchmarks!
@@ -351,4 +348,4 @@ Stack trace (most recent call last):
          24:     blocks.arithmetic.q_1().emplace_back(in.a_scaling);
          25:     blocks.arithmetic.q_2().emplace_back(in.b_scaling);
 gate number4
-```
+```