Add modules infos in README

README.adoc

@@ -7,10 +7,29 @@ A smash.gg-aware local-results generator for Super Smash Brothers Ultimate.
 Requirements
 ------------
 
+=== Modules
+- *jinja2* is the only mandatory external module
+- *cairosvg* can be used for some rasterized exports (see corresponding
+  section)
+
 === Templates
 The *rebootlyon* template needs the *Impact* font (available by default on
 Windows, install +ttf-mscorefonts-installer+ on Ubuntu or Debian).
 
+=== Exports
+The default and preferred output format is *SVG*.
+
+You can also export to *PNG*, *PDF* and *PS* by using the corresponding
+extension in the filename supplied to +--outfile+. Those exports are based on
+the *SVG* output.
+
+To export in *PNG*, lokrez will first try to use *Inkscape* command line. If
+that fails (inkscape is not install, or lokrez can't find it in your PATH), it
+will try to use the *cairosvg* module (which can create artefacts for some SVG
+objects).
+
+To export in *PDF* or *PS*, lokrez will try to use the *cairosvg* module.
+
 === Images
 The SSBU characters images are not included (since this is both copyrighted
 work and a lot of heavy bitmaps), you'll have to get them by your own means and