WIP: Tutorial.

[amanagr]

This PR brings following changes:

• Shows a Tutorial at startup.
• Allows user to change settings before loading UI.

[amanagr]

I think this is mostly ready feature wise, only things remaining are:

• Adding tests
• Improve Tutorial
• Restructure commits.

I would appreciate any feedback on this! (code wise too)

[sumanthvrao]

@amanagr I had a go with this today. It's great overall! :+1: I had few topics to address/request. Futher discussion can take place on these of course :

• Using h to skip tutorial hence-forth is a nice touch. But suppose, I want to again enable it on startup then the only way I can do that is by changing the zulilprc tutorial flag manually. So, perphaps, like we do with the theme setting, we can add a flag (--enable-tutorial = True) so that the arg-parser can use it to override the setting in zuliprc
• The only thing I felt odd about the startuppage was the way text was aligned. Maybe we can stick to left/right indentation rather than centre. Not sure how this will look though.

I skimmed through the code in each commit but haven't yet done an indepth code-wise review.

[amanagr]

@sumanthvrao I thinking of doing a followup PR after this where we can toggle any setting in the LoadingView. User can just press a to switch from autohide to no_autohide and so on...

[amanagr]

@neiljp this is already getting hard to manage, can we merge some initial commits?

[amanagr]

@neiljp @sumanthvrao I would love to have this PR reviewed before proceeding further with writing tests. This brings a huge change to how zt loads up and I would welcome suggestions on if we would do it better in a different way.

[amanagr]

@sumanthvrao thanks for your thoughts. I will look into them.

[zulipbot]

Heads up @amanagr, we just merged some commits that conflict with the changes your made in this pull request! You can review this repository's recent commits to see where the conflicts occur. Please rebase your feature branch against the upstream/master branch and resolve your pull request's merge conflicts accordingly.