Add changelog for v3.0.0

[consideRatio]

• closes Add changelog for version 3.0 #125, which became outdated

I have written the preliminary date for the v3.0.0 release for 19th March (tomorrow).

To address @manics review comment in https://github.com/jupyterhub/jupyter-remote-desktop-proxy/pull/125/files#r1684089648, I pushed dd81df5.

[github-actions]

👈 Launch a binder notebook on this branch for commit 73514f0

I will automatically update this comment whenever this PR is modified

👈 Launch a binder notebook on this branch for commit dd81df5

👈 Launch a binder notebook on this branch for commit 5be6baf

👈 Launch a binder notebook on this branch for commit e2e254b

👈 Launch a binder notebook on this branch for commit f82e721

[consideRatio]

@sunu this includes a breaking change affecting you with the removal of websockify, @yuvipanda wrote in #125:

I choose to make it 3.0 because not needing websockify is a big enough change that will break some dependent projects that relied on using it to detect if the X server was up or not (like https://github.com/sunu/jupyter-remote-qgis-proxy/blob/baf0d373c2f965a60bc6fe038bb04cacc8df8cf5/jupyter_remote_qgis_proxy/utils.py#L44)

[sunu]

Thanks for the heads up @consideRatio!

[consideRatio]

Thank you for the code suggestions @manics!! What do you think - okay to release?

[manics]

Go ahead and release!