feat: refactor codebase to TypeScript

BREAKING CHANGE: API now accessed via returned object when calling
finput() rather than accessed directly on element itself

Author: oriondean

.babelrc

@@ -0,0 +1,29 @@
+import {ActionType, Key} from "./src/constants";
+
+interface IState {
+    value: string;
+    caretStart: number;
+    caretEnd: number;
+    valid: boolean;
+}
+
+interface IKeyInfo {
+    keyName: Key;
+    modifierKeys: string[];
+}
+
+interface IOptions {
+    thousands: string;
+    decimal: string;
+    fixed: boolean;
+    range: number;
+    scale: number;
+    shortcuts: { [shortcut: string]: number }
+}
+
+interface IActionType {
+    type: ActionType;
+    names: string[];
+    // TODO: does this need to be an array? seems like all options only have one
+    modifierKeys: Key[];
+}