fix: fix findUp for Windows (#640)

Co-authored-by: Guillaume Chau <[email protected]>

packages/histoire/src/node/util/find-up.ts

@@ -2,9 +2,14 @@ import path from 'pathe'
 import fs from 'node:fs'
 
 export function findUp (cwd: string = process.cwd(), fileNames: string[]): string {
-  const { root } = path.parse(cwd)
+  let { root } = path.parse(cwd)
   let dir = cwd
 
+  // On Windows, it will for example return `C:`, we need to add the trailing `/`
+  if (root[1] === ':' && root[2] === undefined) {
+    root += '/'
+  }
+
   while (dir !== root) {
     for (const fileName of fileNames) {
       const searchPath = path.join(dir, fileName)