updated readme.

README.md

@@ -1 +1,50 @@
 # pandoc-slide-filter
+
+Collection of pandoc-filters for our reveal-js slides.
+
+## How to build
+
+1. [install stack](https://haskell-lang.org/get-started) and do a `stack setup`
+2. clone this repository
+3. do a `stack build` or `stack install`
+
+`stack build` builds the files but leaves them in `.stack-work/dist/$OS/Cabal-$Cabalversion/build/$exe-dir/$exe-name`.
+`stack install` installs them into `$HOME/.local/bin` (or similar on other OSes).
+
+## What is what?
+
+### Media
+
+support for
+
+- `![](foo.aac){#audio}`
+- `![](foo.mp4){#video}`
+- `![](foo.png){#img}`
+- `![](foo.svg){#svg}`
+- `![](foo.html){#demo}`
+
+### Styling
+
+support for
+
+- `<div id="col" .w50></div>`
+- better code-blocks
+- `<div class="fragment"></div>` region revealed after click
+- `<div class="frame"></div>` region revealed and then vanishes on next click
+- `[]{.fragment}` same for inline-objects
+- `[]{.frame}` same for inline-objects
+- `[]{#hspace width=100px}` manual spacing
+- `[]{#vspace height=100px}` manual spacing
+
+### Quiz
+
+support for
+
+- `[answer-text](tooltip){.answer .right width=100px}`
+- `[answer-text](tooltip){.answer .wrong}`
+
+Note: Tooltip is broken for this syntax, so this might be subject to change.
+
+### Clean
+
+Small filter for cleaning empty Blocks if they get generated.