Fix the initial file setup for @stlite/desktop on Windows

[whitphx]

Resolves #465

[whitphx]

c2dfccd failed the test on Windows as below:

Run yarn test
  yarn test
  shell: C:\Program Files\PowerShell\7\pwsh.EXE -command ". '{0}'"
yarn run v1.[2](https://github.com/whitphx/stlite/actions/runs/3970187350/jobs/6806089699#step:7:2)2.19
$ craco test
FAIL electron/__tests__/file.test.ts
  walkRead
    × walks in the specified directory, reads the all child file contents, and returns the pairs of the relative path and the file content (25 ms)
    × walks in the specified directory, reads the all child file contents, and returns the pairs of the absolute path and the file content if relative=false (4 ms)

  ● walkRead › walks in the specified directory, reads the all child file contents, and returns the pairs of the relative path and the file content

    expect(received).toEqual(expected) // deep equality

    - Expected  - 1
    + Received  + [3](https://github.com/whitphx/stlite/actions/runs/3970187350/jobs/6806089699#step:7:3)

    @@ -1,7 +1,7 @@
      Object {
    -   "bar/bar.txt": Object {
    +   "bar\\bar.txt": Object {
          "data": Array [
            99,
            111,
            110,
            115,
    @@ -26,10 +26,11 @@
            32,
            101,
            108,
            105,
            116,
    +       13,
            10,
          ],
          "type": "Buffer",
        },
        "foo.txt": Object {
    @@ -58,10 +59,11 @@
            32,
            97,
            109,
            101,
            116,
    +       13,
            10,
          ],
          "type": "Buffer",
        },
      }

       6 |     const targetDirPath = path.resolve(__dirname, "./foo/");
       7 |     const result = await walkRead(targetDirPath);
    >  8 |     expect(result).toEqual({
         |                    ^
       9 |       "foo.txt": Buffer.from("Lorem ipsum dolor sit amet\n"),
      10 |       "bar/bar.txt": Buffer.from("consectetur adipiscing elit\n"),
      11 |     });

      at Object.<anonymous> (electron/__tests__/file.test.ts:8:20)

  ● walkRead › walks in the specified directory, reads the all child file contents, and returns the pairs of the absolute path and the file content if relative=false

    expect(received).toEqual(expected) // deep equality

    - Expected  - 0
    + Received  + 2

    @@ -26,10 +26,11 @@
            32,
            101,
            108,
            105,
            116,
    +       13,
            10,
          ],
          "type": "Buffer",
        },
        "D:\\a\\stlite\\stlite\\packages\\desktop\\electron\\__tests__\\foo\\foo.txt": Object {
    @@ -58,10 +59,11 @@
            32,
            97,
            109,
            101,
            116,
    +       13,
            10,
          ],
          "type": "Buffer",
        },
      }

      15 |     const targetDirPath = path.resolve(__dirname, "./foo/");
      16 |     const result = await walkRead(targetDirPath, false);
    > 17 |     expect(result).toEqual({
         |                    ^
      18 |       [path.resolve(targetDirPath, "./foo.txt")]: Buffer.from(
      19 |         "Lorem ipsum dolor sit amet\n"
      20 |       ),

      at Object.<anonymous> (electron/__tests__/file.test.ts:17:20)

Test Suites: 1 failed, 1 total
Tests:       2 failed, 2 total
Snapshots:   0 total
Time:        [4](https://github.com/whitphx/stlite/actions/runs/3970187350/jobs/6806089699#step:7:5).02[7](https://github.com/whitphx/stlite/actions/runs/3970187350/jobs/6806089699#step:7:8) s
Ran all test suites.
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
Error: Process completed with exit code 1.

It was solved with 2e8a7f9