Add immediate observer callback invokation

[krypt102]

Fixes #166
Basically just runs the callback immediately while still providing a disconnect function.
Will be a draft for the moment until I implement disconnecting

[krypt102]

Nevermind, that was surprisingly easier than I thought

[dphfox]

Looks good to me :)

[Dionysusnu]

Solves #166

FYI, if you replace "Solves" with fixes or closes, GitHub will automatically close the linked issue when a Pull Request is merged into the main branch.

For example: "closes #166"

https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword

[krypt102]

Solves #166

FYI, if you replace "Solves" with fixes or closes, GitHub will automatically close the linked issue when a Pull Request is merged into the main branch.

For example: "closes #166"

https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword

Ohhhh, thank you! That's why it wasn't showing before 😆