[8.x] Fix mobile horizontal scroll on Sanctum page

[timothepearce]

Issue

The current Sanctum page has a horizontal scroll on mobile devices as you can see on the screenshot below:

Fix

I replaced the <code> tag with a <pre> one to avoid the overflow.

[driesvints]

I'm thinking we should rather fix the breakage itself rather than adjusting the content. Although this is a good intermediary fix.

[timothepearce]

Thanks, Dries! You're right, I'll make a PR in the website repo.

[timothepearce]

@driesvints Here is the fix: laravel/laravel.com#153