adding 'TabStack.sublime-settings' and "preview_file" setting

[d0vgan]

Updating TabStack to store its settings in 'TabStack.sublime-settings', adding a "preview_file" setting.
Note: with "preview_file" set to false, it is recommended to also set "animation_enabled" to false. Otherwise you'll be seeing the tab scrolling animation each time you switch to another file when the Ctrl key has been released. (According to AI, there is no ability to temporarily change that setting in memory - and I definitely don't want to read and write the physical settings file on each Ctrl+Tab).

[d0vgan]

I'm not sure whether we really need these "Settings - Default", but other packages contain that

[FichteFoll]

We would want to use the edit_settings command like #12 does instead of providing two separate commands.

[d0vgan]

I'm afraid I don't understand how to adapt the edit_settings.
Should I just revert my version of "Main.sublime-menu" since it's already present in your PR?
Or should I copy-paste your implementation and add something there? If so, what should I add?

[FichteFoll]

Don't worry about it. It was just meant as an FYI since I won't be merging this PR either way since it has too many conflicts and the one thing still left, the preview_file setting, I would rather do on my own.

[FichteFoll]

As mentioned in #10, I have a fix ready for this already in #12.

However, this pull request also adds a new setting that has not been discussed before. Can you elaborate a bit on why you added it? Perhaps also include a screen recording so I can get a better understanding of why one would want to disable this functionality?

Previously, I actively decided against making this configurable and to avoid having to add a settings file entirely, but via #12 I had to add a setting so not having a settings file is not an argument anymore. Still, I would like to keep configuration options to a minimum and provide a good, universal default experience.

[d0vgan]

However, this pull request also adds a new setting that has not been discussed before.
Can you elaborate a bit on why you added it?

The setting

"preview_file": false

provides the same Ctrl+Tab user experience as VS Code, Visual Studio, Notepad++, Cuda Text (with ui_tab_switcher_dialog enabled) and many other text editors.
What it does: the active file is changed only when Ctrl has been released, not while another item is selected in the TabStack list. It provides smoother navigation through the TabStack list because the time is not spent on activating another file each time another item is selected in the list.
Here is a short screen recording demonstrating that (the active file remains unchanged until Ctrl is released):

As I mentioned, the best user experience is achieved with SublimeText's setting animation_enabled set to false because it avoids the tab scrolling animation when Ctrl is released.

[FichteFoll]

It provides smoother navigation through the TabStack list because the time is not spent on activating another file each time another item is selected in the list.

I personally disagree about not having the file preview being smoother since now you get the file changed while is is "in focus" instead of in the background while the quick panel is open, but that was indeed the answer I was looking for with that question. Since, as I mentioned, we already have a settings file anyway, adding this as an option isn't much of an issue anymore and I will do so before the next release on the weekend.