docs: update the verifier contract paths in book (#1587)

Co-authored-by: Yi Sun <[email protected]>

Author: HrikB

book/src/writing-apps/verify.md

@@ -48,12 +48,12 @@ This command can take ~20mins on a `m6a.16xlarge` instance due to the keygen tim
 Upon a successful run, the command will write the files
 
 - `agg.pk`
-- `halo2/Halo2Verifier.sol`
-- `halo2/OpenVmHalo2Verifier.sol`
-- `halo2/interfaces/IOpenVmHalo2Verifier.sol`
-- `halo2/verifier.bytecode.json`
+- `halo2/src/[OPENVM_VERSION]/Halo2Verifier.sol`
+- `halo2/src/[OPENVM_VERSION]/OpenVmHalo2Verifier.sol`
+- `halo2/src/[OPENVM_VERSION]/interfaces/IOpenVmHalo2Verifier.sol`
+- `halo2/src/[OPENVM_VERSION]/verifier.bytecode.json`
 
-to `~/.openvm/`, where `~` is the directory specified by environment variable `$HOME`. Every command that requires these files will look for them in this directory.
+to `~/.openvm/`, where `~` is the directory specified by environment variable `$HOME` and `OPENVM_VERSION` is the version of OpenVM. Every command that requires these files will look for them in this directory.
 
 The `agg.pk` contains all aggregation proving keys necessary for aggregating to a final EVM proof.
 The `OpenVmHalo2Verifier.sol` file contains a Solidity contract to verify the final EVM proof. The contract is named `OpenVmHalo2Verifier` and it implements the `IOpenVmHalo2Verifier` interface.