add purpose, examples, depends

Signed-off-by: first <first@noreply.git.r21.io>

README.md

@@ -1,4 +1,13 @@
 # backup2mdisc
+
+## Purpose:
+1. Scans all files in a source directory.
+2. Groups them into "chunks" so that each chunk is <= a specified size (default 100GB).
+3. Creates a TAR archive of each chunk, compresses it with `lz4`, and encrypts it with GPG (AES256).
+4. Each `.tar.lz4.gpg` is fully independent (no other parts/discs needed to restore that chunk).
+5. (Optional) Creates ISO images from each encrypted chunk if `--create-iso` is provided.
+6. (Optional) Burns each chunk or ISO to M-Disc if `--burn` is provided.
+
 ## How It Works
 
 1. **File Collection & Sorting**  
@@ -35,6 +44,25 @@
 
 ---
 
+## Usage:
+`./backup_in_individual_chunks.sh /path/to/source /path/to/destination [CHUNK_SIZE] [--create-iso] [--burn]`
+
+## Examples:
+`./backup_in_individual_chunks.sh /home/user/data /mnt/backup 100G --create-iso`
+`./backup_in_individual_chunks.sh /data /backup 50G --burn`
+
+## Dependencies:
+- `bash`
+- `gpg` (for encryption)
+- `lz4` (for fast compression)
+- `tar`
+- `split` or file-based grouping approach
+- `sha256sum` (or '`shasum -a 256`' on macOS/FreeBSD)
+- `genisoimage` or `mkisofs` (for creating ISOs if `--create-iso`)
+- `growisofs` (Linux) or `hdiutil` (macOS) for burning if `--burn`
+
+---
+
 ## Restoring Your Data
 
 - **Disc is self-contained**: If you have disc #4 containing `chunk_004.tar.lz4.gpg`, you can restore it independently of the others.