Generate receipts for contributions

I based the pandoc stuff on a blog post[1] I found. I've generated 4
receipts for the contributions in
`statements/statement_2019-04-17_2019-06-03.pdf`.

[1] https://medium.com/@martin_betz/generate-pdf-invoices-from-markdown-using-pandoc-5cb3fe84ba3a

README.md

@@ -1,3 +1,18 @@
-# fund
+# Fund
 
-Records and documentation for the CoTech fund
+Records and documentation for the CoTech fund
+
+## Generating receipts
+
+Install `pandoc` and `wkhtmltopdf` using, for example homebrew on OS X
+
+```
+brew install pandoc
+brew install Caskroom/cask/wkhtmltopdf
+```
+
+Then in `receipts/` create a markdown file from an existing one, and run, for example
+
+```
+pandoc -t html5 agile_collective_2019-2020.md -o agile_collective_2019-2020.pdf --css style.css
+```