add node-webvtt for parsing subtitles

package.json

@@ -16,6 +16,7 @@
     "json5": "^2.2.0",
     "lodash.throttle": "^4.1.1",
     "nanoid": "^4.0.0",
+    "node-webvtt": "^1.9.4",
     "ofetch": "^1.0.0",
     "pako": "^2.1.0",
     "react": "^17.0.2",

src/types/node_webtt.d.ts

@@ -0,0 +1,27 @@
+declare module "node-webvtt" {
+  interface Cue {
+    identifier: string;
+    start: number;
+    end: number;
+    text: string;
+    styles: string;
+  }
+  interface Options {
+    meta?: boolean;
+    strict?: boolean;
+  }
+  type ParserError = Error;
+  interface ParseResult {
+    valid: boolean;
+    strict: boolean;
+    cues: Cue[];
+    errors: ParserError[];
+    meta?: Map<string, string>;
+  }
+  interface Segment {
+    duration: number;
+    cues: Cue[];
+  }
+  function parse(text: string, options: Options): ParseResult;
+  function segment(input: string, segmentLength?: number): Segment[];
+}

tsconfig.json

@@ -16,6 +16,7 @@
     "noEmit": true,
     "jsx": "react-jsx",
     "baseUrl": "./src",
+    "typeRoots": ["./src/types"],
     "paths": {
       "@/*": ["./*"]
     },