Improvement of app sidebar design

[DonKoko]

So I was looking at our app's UI and I also had stripe open at the same time and I realized that their sidebar looks so much cleaner. Also it didn't look too overwhelming and that its taking too much space. Here are 2 screenshots for comparison. Both screenshots are taken on the same browser and at 100% scale.

Stripe:

Shelf:

So now that we are getting more and more items in the sidebar I feel it starts to get cluttered and a bit overwhelming.
@jurrejansen @carlosvirreira what do you guys think? Can we rethink/resize a bit the items to make it a bit cleaner?

A few more ideas:

• I really like their way of pinning items to the sidebar. That is complete user agency and we talk about that a lot so it can be nice for the users, especially since we are starting to get more and more items there
• Foldable items - I think this can be very useful for menu items that are related to the same concept. For example we could have:

- Bookings
  - Overview
  - Calendar

[jurrejansen]

@DonKoko @carlosvirreira all for improving the sidebar and making it more minimal and taking up less space perhaps.

Amount of menu items
We could also consider moving some items under Settings (Categories, Tags, Locations)

Foldable items
Not sure how often this is going to be relevant. Maybe good to look at planned features/concepts and see if they can be grouped. Also for booking and calendar I feel this could also be an option.