docs: update class names in theming guide

[Lehoczky]

Hi there 👋

I was following the theming section recently and found two little things that I thought could be improved. Let me know what you think!

And also, thank you for the library<3

🚀 What's changed?

• The curly braces are now correctly escaped in the theming guide

Before:

After:

• The CSS selectors for the .selected and .animated classes has been updated. They can be copy-pasted now from to docs to someone's custom CSS file.

Before, they were used as child selector, which doesn't work:

/* This doesn't work, because the "selected" class is
    added directly to the node:*/
.vue-flow__node .selected {
  background: red
}

/*This works:*/
.vue-flow__node.selected {
  background: red
}

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Name	Status	Preview	Comments	Updated (UTC)
vue-flow-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Feb 11, 2024 10:20pm

[bcakmakoglu]

Thanks! :)