Rename project to 'iocrypter' and update README details.

The README has been updated to reflect the new name 'iocrypter' and provide a detailed description of its functionality. Licensing information and example usage instructions were also added to enhance clarity and usability.

README.md

@@ -1,9 +1,22 @@
-# filecrypter
-
-```
-                          Message Format
-+----------------------------------------------------------+
-| scryptIterations | randSalt | randIV | cipherText | hmac |
-+----------------------------------------------------------+
-      (32)            (256)     (128)    (varies)    (512)
-```
+<!--
+SPDX-FileCopyrightText: Winni Neessen <wn@neessen.dev>
+
+SPDX-License-Identifier: MIT
+-->
+
+# iocrypter
+
+iocrypter is a Go package that implements AES-256-CTR encryption with SHA-512 HMAC authentication
+as a `io.Reader` interface. It allows the en- and decryption with authentication of arbitrary data 
+from any given `io.Reader`.
+
+It derives a secure key for the AES-256 encryption using Argon2ID. Encryption parameters like the 
+Argon2 settings, the salt and the IV are stored at the start of the ciphertext, making it convenient 
+for byte stream encryption.
+
+The [cmd/](cmd) directory holds two example implementations for tools that will read a file from
+disk and then en- or decrypt it accordingly.
+
+## License
+
+This project is licensed under the MIT License. See the LICENSE file for details.