add a readme

README.md

+# revtex-markdown-paper
+
+REVTeX paper in markdown using LaTeX.
+
+The paper (`paper.md`) is written in [Markdown](https://daringfireball.net/projects/markdown/) and then translated to LaTeX using [pandoc](http://pandoc.org/) and the `revtex.template`.
+References are in `paper.bib` using the [BibTeX](http://www.bibtex.org/) format.
+
+The `Makefile` contains the conversion commands.
+If you are on a unix system, call `make paper.pdf` in this directory and it will compile the paper to `pdf` if all dependencies are installed.
+
+## Usage
+
+Make sure you have a working TeX installation and then
+
+1. Install the dependencies
+
+    ~~~{bash}
+    conda-env create -f environment.yml
+    ~~~
+2. Clone this repository
+
+    ~~~{bash}
+    git clone https://github.com/basnijholt/revtex-markdown-paper.git
+    ~~~
+3. Write paper in `paper.md`, refs in `paper.bib`, compile with `make paper.pdf`
+
+The file `paper.md` contains example code for tables, figures, equations, references and so on.