Function changes need for Bazel

[aydinmetee]

Hi, I tried to use this library in Bazel. But in build process, Some files couldn't find. In my opinion, It's related to build process in bazel.
We can replace "readDir" function with "readdirSync". I forked the project and replace the function. "readdirSync" function can be more effective for asyncron process. I made some tests and I saw no error.
I can use forked version. But I think, if we replace the function, It will be more useful.
What do you think about this?

ros-typescript-generator/src/lib/readMsgFiles.ts

Line 9 in e8d0406

for (const entry of await readdir(dir, { withFileTypes: true })) {