Repo organizing

- Add doc/ directory, so publishing to gh-pages is a bit easier.
- Update .gitignore to not ignore the doc/ directory.

- Move manual documentation directory into new var directory (var/docs)
- Move example dialogue tree into new var directory (var/trees)
- Update YARD to find manual documentation in new var directory

var/docs/editor.md

@@ -0,0 +1,16 @@
+<!--
+# @markup markdown
+# @title Using the Editor
+-->
+# Sapling Editor
+
+Sapling provides an editor for creating and modifying dialogue trees. The editor
+allows for editing all parts of a tree, from the trunk to the leaves.
+
+## Creating a new tree
+
+Pending
+
+## Editing an existing tree
+
+Pending