Start using Yard

- Add yard to Gemfile
- Configure .yardopts to pull in proper files
- Update custom docs to include yard metadata

docs/config_file.md

@@ -1,3 +1,8 @@
+<!--
+# @markup markdown
+# @title Configuration File
+-->
+
 # Configuration File Documentation
 
 The configuration file for `sapling` is a standard YAML file. The general

docs/config_file_example.md

@@ -0,0 +1,42 @@
+<!--
+# @markup markdown
+# @title Example YAML File
+-->
+# Example Dialogue Tree
+    ---
+    # The trunk is a general introduction to the tree. It shouldn't include any
+    # thematic details, rather a one-liner to let the user know what they're getting
+    # into.
+    -
+      trunk: "This is a general introduction to the dialogue tree."
+
+    # Branches are the content of a dialogue tree. Each branch is numbered, and that
+    # number is used as the primary means of navigation. The text of a branch is the
+    # story provided to the user; the result of getting to the branch. The leaves
+    # (the section titled leaf) represent the options. Options are displayed in the
+    # order they appear. Within a leaf, the text is what the option says, and the
+    # branch is the branch number which this option will lead to. Leading to branch
+    # number 0 will immediately exit the program.
+    #
+    # You can have as many branches and leaves as you wish, though having too many
+    # leaves may lead to both display problems, and paralyzing indecision.
+    -
+      branch:
+        number: 1
+        text: "The first branch. Displayed first, by default."
+        leaf:
+          -
+            text: "The first option for this branch. It leads to branch 2"
+            branch: 2
+          -
+            text: "The second branch. It immediately exits the program."
+            branch: 0
+
+    # A terminal branch is a branch which has no leaves. This represents an ending.
+    # Once a user hits a terminal branch, the program will display the branch text,
+    # and then redirect the user to branch 0, to exit.
+    -
+      branch:
+        number: 2
+        text: "This is a terminal branch. After displaying this text,
+          the program will exit."

docs/config_file_example.yaml

@@ -1,3 +1,4 @@
+# @title Example YAML File
 ---
 # The trunk is a general introduction to the tree. It shouldn't include any
 # thematic details, rather a one-liner to let the user know what they're getting

docs/editor.md

@@ -1,3 +1,7 @@
+<!--
+# @markup markdown
+# @title Using the Editor
+-->
 # Sapling Editor
 
 Sapling provides an editor for creating and modifying dialogue trees. The editor