Updated documentation

Signed-off-by: spv <spv0x04@proton.me>

README.md

@@ -4,3 +4,20 @@ my rsa implementation in rust using as few libraries as my mental wellbeing coul
 Im using clap so documentation is not really required the binary documents itself.
 
 idk
+
+
+## Usage
+1. Generate a pair of keys
+```bash
+./rsa generate <-b/--bitsize keysize>
+```
+2. Encrypt some data with public key
+```bash
+./rsa encrypt public_key "Hello"
+```
+Will write the encrypted data to `message.enc`
+3. Decrypt it
+```bash
+./rsa private_key message.enc
+```
+Will print `Hello`