update extract_into(), add example for bundles and add restart() method

[hacknus]

Closes #145.

I had to update the extract_into() method such that it works for bundles/directories that are zipped.
Additionally, I added an example in the README.md to describe the usage with bundles (specifically on macOS). For this example, we might consider putting the copy_dir() also in this library, but for now I leave it like that.

Furthermore, I included the restart.rs file with a restart() method that launches a zombie process of the own instance, allowing users to automatically restart the application after self_replace() has been called.

[hacknus]

Can this be merged?

[hacknus]

^bump

[hacknus]

weird, when I push, the publish workflow is automatically called - which fails in my fork, because I don't have the credentials, obviously. this should probably on run on creating a new release, and not everytime, right?

also, the check_readme failed because I added an example to the readme. you don't allow changes to the readme?

[GideonBear]

weird, when I push, the publish workflow is automatically called - which fails in my fork, because I don't have the credentials, obviously. this should probably on run on creating a new release, and not everytime, right?

@jaemk this is your domain...
In any case, the workflow could probably be limited using if: github.repository == 'jaemk/self_update'

also, the check_readme failed because I added an example to the readme. you don't allow changes to the readme?

We do, but these need to be included in the doc comment in lib.rs and then compiled using cargo-readme.