Add state handler implementations and documentation

- Implemented StateHandler class with methods for entering, exiting, and updating states.
- Created TypeStateHandler for handling typing state with appropriate animations and transitions.
- Developed WaitStateHandler for managing idle state with quirk animations.
- Added JSDoc documentation for all new classes and methods.
- Included CSS styles for documentation formatting and syntax highlighting.

docs/scripts/linenumber.js

@@ -0,0 +1,25 @@
+/* global document */
+(() => {
+  const source = document.getElementsByClassName('prettyprint source linenums')
+  let i = 0
+  let lineNumber = 0
+  let lineId
+  let lines
+  let totalLines
+  let anchorHash
+
+  if (source && source[0]) {
+    anchorHash = document.location.hash.substring(1)
+    lines = source[0].getElementsByTagName('li')
+    totalLines = lines.length
+
+    for (; i < totalLines; i++) {
+      lineNumber++
+      lineId = `line${lineNumber}`
+      lines[i].id = lineId
+      if (lineId === anchorHash) {
+        lines[i].className += ' selected'
+      }
+    }
+  }
+})()