[FEATURE] Add a guide on how to use the app

[Glitchy-Tozier]

Is your feature request related to a problem? Please describe.
I'd like to propose adding a guide, explaining what the app's features are and how to use them.
Currently, I do understand that there's a system of declaring habits and checking whether they've been implemented each day. However, everything further doesn't seem self-explanatory. For example:

• When checking off a habit, what's the difference between ×, – and ??
• What's the thing circled in the attached screenshot? Is it an absolute value? Is it the target nr of days for each year?
• Does the "Goal" number affect anything? Or is it, as with the goal's unit, just some basic information, collected only to be displayed?

Describe the solution you'd like
I think a guide could help. A neat fornat might be to walk the user through fully setting up and checking off a habit, explaining each action along the way.

Describe alternatives you've considered
A regular written guide could be useful, too. However, having lots of screenshots could surely improve accessibility.

Additional context

[FriesI23]

Add app user guide

[plutonium-239]

Hello, a user guide would be pretty useful. Is there any update on it since it has been 6 months since the last comment?

It's unclear how weekly goals should be added and updated, since there is only an option for a daily goal. For example, I want to track charging my mouse which is usually once a week. Currently, I have it set to daily goal of 0.14 so that in 7 days it adds up to ~1, but I don't think that is the correct way of doing it.

It's also unclear what "undone" means when long pressing a tick from the home screen.