Format function names in CHANGELOG.md with backticks.

Author: agrojean-ledger

CHANGELOG.md

@@ -10,7 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 * AI review : fix command injection vulnerability (only use trusted instruction files + use spawnSync instead of execSync)
-* AI review : block path traversal in ledger_readFile and ledger_grepCode tools
+* AI review : block path traversal in `ledger_readFile` and `ledger_grepCode` tools
 
 ## [2.5.1]