README update

README.md

@@ -3,6 +3,16 @@
 Cli tool in Rust to encrypt and decrypt files with an Ascon-Keccak AEAD.  
 The PBKDF used is Argon2id.
 
+## tests
+```bash
+cargo test
+```
+
+## build
+```bash
+cargo build --release
+```
+
 ## Commands
 
 ### Encrypt a file