Added TS Type declaration

package.json

@@ -9,6 +9,7 @@
     "quill-delta": "^4.2.1"
   },
   "devDependencies": {
+    "@types/node": "^14.14.22",
     "chai": "^4.2.0",
     "lodash": "^4.17.15",
     "mocha": "^6.1.4",

types/rich-text/index.d.ts

@@ -0,0 +1,60 @@
+declare module "rich-text" {
+    import Delta, {Op} from 'quill-delta';
+
+    const name: string;
+    const uri: string;
+
+    function create(initial?: Op[] | { ops: Op[] }): Delta;
+    function compose(delta1: Op[] | { ops: Op[] }, delta2: Op[] | { ops: Op[] }): Delta;
+    function diff(delta1: Op[] | { ops: Op[] }, delta2: Op[] | { ops: Op[] }): Delta;
+
+    function transform(
+        delta1: Op[] | { ops: Op[] },
+        delta2: Op[] | { ops: Op[] },
+        side: string
+    ): Delta|number;
+
+    function transformCursor(
+        cursor: number,
+        delta: Delta,
+        isOwnOp: boolean
+    ): number;
+
+    function normalize(delta: Delta): Delta;
+    function serialize(delta: Delta): Op[];
+    function deserialize(ops: Op[]): Delta;
+
+    interface IRange {
+        index: number;
+        length: number
+    }
+
+    function transformPresence(
+        range: IRange,
+        op: Op,
+        isOwnOp: boolean
+    ): IRange
+
+    const type = {
+        name,
+        uri,
+        create,
+        apply,
+        compose,
+        diff,
+        transform,
+        transformCursor,
+        normalize,
+        serialize,
+        deserialize,
+        transformPresence
+    }
+
+    module.exports = {
+        Delta,
+        type
+    }
+
+    export = type
+
+}