Documentation. (#12)

* First docs.

* Docs requirements.

* Add auto-generated gallery and fix two bugs in the driver.

* Gallery: link directly to github.

* Tag examples as Haskell code.

* Update starting guide and redirect gallery links to master branch.

* Include link to readthedocs.


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docs/index.md

@@ -0,0 +1,24 @@
+# Getting started
+
+## Viewing a basic animation
+
+```console
+$ git clone https://github.com/Lemmih/reanimate.git
+$ cd reanimate/
+$ stack build
+$ stack ./examples/raster.hs
+```
+
+## Checking dependencies
+
+Reanimate includes a run-time for optional dependencies.
+
+```console
+$ stack ./examples/raster.hs check
+```
+
+## Rendering movies
+
+```console
+$ stack ./examples/raster.hs render
+```