source does not execute main as default

[JPBeckner]

Describe the bug

Invoking source --help it says:

(...) Runs foo.nu in current context and call the `main` command automatically, (...)

But it does not happens:

/home/me/nu-report〉touch foo.nu                                                                                   04/20/2022 11:06:06 AM
/home/menu-report〉nvim ./foo.nu                                                                                  04/20/2022 11:06:11 AM
/home/menu-report〉cat ./foo.nu                                                                                   04/20/2022 11:06:25 AM
def main [] { echo 'Hi!' }
/home/me/nu-report〉chmod +x ./foo.nu                                                                              04/20/2022 11:06:28 AM
/home/me/nu-report〉source ./foo.nu                                                                                04/20/2022 11:06:32 AM
/home/me/nu-report〉source ./foo.nu; main                                                                          04/20/2022 11:06:46 AM
Hi!

How to reproduce

1. Create a .nu file with the content: def main [] { echo 'Hi!' }

touch foo.nu
nvim ./foo.nu  # write the file
cat ./foo.nu
# def main [] { echo 'Hi!' }

2. Give execution permission to the file.

chmod +x ./foo.nu

3. Try source

source ./foo.nu
# nothing
source ./foo.nu; main
# Hi!

### Expected behavior

Is expected that `source` invokes `main` by default, as informed.

### Screenshots

![image](https://user-images.githubusercontent.com/43730756/164250746-5669ad2c-e563-4e50-b7c0-8920f4c8ef20.png)


### Configuration

![image](https://user-images.githubusercontent.com/43730756/164250985-1189aab1-b85b-4ed3-bb33-a98c4aee48fd.png)
| key                | value                               |
| ------------------ | ----------------------------------- |
| version            | 0.61.0                              |
| branch             |                                     |
| tag                |                                     |
| build_os           | linux-x86_64                        |
| rust_version       | rustc 1.60.0 (7737e0b5c 2022-04-04) |
| rust_channel       | stable-x86_64-unknown-linux-gnu     |
| cargo_version      | cargo 1.60.0 (d1fd9fe 2022-03-01)   |
| pkg_version        | 0.61.0                              |
| build_time         | 2022-04-20 09:56:20 -03:00          |
| build_rust_channel | release                             |
| features           | default, trash, which, zip          |
| installed_plugins  |                                     |


### Additional context

_No response_

[fdncred]

i thought main was only invoked if launching a nushell script like nu script_name.nu paramaters versus with source? it seems to work that way for me with your example foo.nu script.