Fixed typo, moved generate-layout script

[spoenemann]

The generate-layout script uses Electron and thus should be moved to a package that has a direct dependency to it.

[spoenemann]

Open question (copied from #4724):

Should we extract the script to a separate repository to make creating keyboard layouts easier, esp. for external contributors? We don't need to build the whole of Theia just to run a simple NodeJS script.

[akosyakov]

@spoenemann Together with generated layouts that other can contribute?

[akosyakov]

The generate-layout script uses Electron and thus should be moved to a package that has a direct dependency to it.

We don't publish generate-layout script layout right now. And electron is always hoisted to root, so yarn can find it from any place in the project. Do you really want to move it?

[spoenemann]

Together with generated layouts that other can contribute?

Those need to be in @theia/core so we can use them directly (unless we publish an external package dedicated to this purpose and depend on it).

electron is always hoisted to root

Nevermind then.