Add README.md

README.md

+# PNG to SVG
+
+It converts png images to SVG vectors.
+
+That'is it.
+
+## Installation
+
+### From Source
+
+1. Clone this repository
+2. Run "cargo build --release"
+3. Copy `target/release/png_to_svg` to somewhere in your system's `$PATH`
+
+### Prebuilt (Linux)
+
+1. Use your favourite method (curl, wget, browser, etc) to download the latest binary: `https://lab.lcr.gr/microhacks/png-to-svg/-/jobs/artifacts/trunk/raw/png_to_svg?job=build:application`
+2. Copy `png_to_svg` to somewhere in your system's `$PATH`
+
+## Usage
+
+```bash
+$: png_to_svg --help
+Convert RGBA8 PNG images into SVGs, where each pixel of input creates one output rect
+
+Usage: png_to_svg [OPTIONS] <INPUT_FILE> <OUTPUT_FILE>
+
+Arguments:
+  <INPUT_FILE>   
+  <OUTPUT_FILE>  
+
+Options:
+  -s, --scale <SCALE>  Set the size of each output pixel; creates an NxN rect for each input pixel where N is the scale [default: 1]
+  -h, --help           Print help information
+  -V, --version        Print version information
+```
+
+### Notes
+
+- The input and output files do not need to have `png` and `svg` suffixes, respectively. Instead, the file types are assumed
+- `-s` and `--scale` will set affect the `width`, `height`, and `viewbox` attributes of the root `<svg>` element, and the `x`, `y`, `width`, and `height` attributes of the pixel `rect` elements
+- The file size of the SVG equivalent is quite large compared to the original PNG