Add Mirrors header.

README.md

@@ -3,11 +3,11 @@ PixelCanvas.io downloader
 
 This utility lets you download the http://pixelcanvas.io bitmap and export regions of it to .png files.
 
-# Requirements
+## Requirements
 
     pip install -r requirements.txt
 
-# Usage
+## Usage
 
 This tool is run from the command line, where you provide the coordinates you
 want to download and render.
@@ -44,7 +44,7 @@ So, for example:
     > pixelcanvas.py render ~1200.300--~900.600 --show
     > pixelcanvas.py render ~2000.2000--2000.2000 --scale 0.25
 
-# To do
+## To do
 
 Here are some things we might like to improve:
 
@@ -52,6 +52,8 @@ Here are some things we might like to improve:
 - Render the image as it appeared at some point in the past, taking advantage of the `updated_at` column.
 - Probably never going to happen: A GUI application to browse the db just like the site.
 
+## Mirrors
+
 https://github.com/voussoir/pixelcanvasdl
 
 https://gitlab.com/voussoir/pixelcanvasdl