Adds b64pack CLI tool with packaging and deployment

Introduces the b64pack CLI tool for packing, encoding, and decoding files or directories into Base64, with essential features and a simple interface.

Sets up automated build and deploy workflow for the tool using Gitea Actions. Includes Poetry configuration for dependency management and packaging.

Fixes copyright metadata and updates documentation in English and German.

README.md

@@ -1,2 +1,52 @@
 # b64pack
 
+**b64pack** is a lightweight CLI tool to pack files or folders into compressed Base64 strings, and decode them back into their original form.
+
+It is useful for creating compact secrets, transferring files as text, or embedding artifacts in pipelines.
+
+## Features
+
+- Pack a single file into `.tar.gz` and encode it as a Base64 string
+- Pack an entire directory into `.tar.gz` and encode as Base64
+- Encode an existing file directly to Base64 (without compression)
+- Decode Base64 strings back into original files
+- Unpack Base64 strings directly into extracted folders
+- One-line output: no line breaks for easy embedding
+- Simple CLI interface without external dependencies
+
+## Installation
+
+```bash
+poetry install
+poetry shell
+```
+
+## Usage
+
+Encode a file:
+
+```bash
+b64pack encode path/to/file.txt
+```
+
+Pack and encode a directory:
+
+```bash
+b64pack pack-dir path/to/folder/
+```
+
+Decode a Base64 string back into a file:
+
+```bash
+b64pack decode path/to/base64.txt -o output.tar.gz
+```
+
+Unpack a Base64 string directly into a folder:
+
+```bash
+b64pack unpack path/to/base64.txt -d output_folder/
+```
+
+## License
+
+MIT License