Include .storybook in deadcode detection

extensions/ql-vscode/scripts/find-deadcode.ts

@@ -6,6 +6,7 @@ import { exit } from "process";
 function ignoreFile(file: string): boolean {
   return (
     containsPath("gulpfile.ts", file) ||
+    containsPath(".storybook", file) ||
     containsPath(join("src", "stories"), file) ||
     pathsEqual(
       join("test", "vscode-tests", "jest-runner-installed-extensions.ts"),

extensions/ql-vscode/tsconfig.deadcode.json

@@ -1,5 +1,5 @@
 {
   "extends": "./tsconfig.json",
-  "include": ["**/*.ts*"],
+  "include": ["**/*.ts*", ".storybook/**/*.ts*"],
   "exclude": ["node_modules"]
 }