[docs] Add Swipe & Scroll guide

[m-bert]

Description

At the beginning of new web implementation Swipeable component was blocking scroll on web. We did fix it by adding touch-action: pan-y; as a property to our handlers, and making it default in Pan used under the hood of Swipeable.

However, some of our users prefer to create their own versions of Swipeable - that's where they encounter this issue.

This PR adds guide section about fixing this problem.

It also changes font size of code inside headers such that it is no longer ridiculously small.

Test plan

Run docs

[patrycjakalinska]

Good fix with small font! ✨ The guide sounds good, one thing I'd do is to change title to more describing like Custom swipeable components inside ScrollView (web) and remove subtitle.

Also, I understand its placement (under Guides section) but it's kinda short for separate page. I'd be perfect if there'll be a better place for it, but I'm not pushing as for now it's pretty acceptable.

[patrycjakalinska]

🚀