feat: Initial launch v0.1.0

Initialize `sized` CLI tool with comprehensive features for directory visualization.

Features:
- Fast parallel directory traversal using `rayon`.
- Rich table output with colors and dual units (Binary/Decimal).
- Recursive sizing with depth control (`-d`).
- Filtering by minimum size (`-m`).
- Sorting by name, type, size, or blocks (`--sort`).
- Gitignore integration (`--ignore`).
- Multiple output formats: Text, CSV, JSON (`--format`).
- Export to file functionality (`--save`).
- Shell completion generation (`--completions`).

test_data/file1.txt

@@ -0,0 +1 @@
+12345

test_data/subdir/file2.txt

@@ -0,0 +1 @@
+1234567890