Add anchors to refer examples

[fernahh]

Problem:

Sometimes we need to share one specific component example. Today it's not a good experience when this component has many examples.

Solution:

Add an anchor on example title.

Examples:

I've liked of SHAPE UP style, where the anchor icon has been showing just on mouseover:

There another example of rbx with a hash:

@rafaelcamargo what you think about it?

[rafaelcamargo]

Would be awesome! ✌️

Since Pitsby has a path always starting with /#!/, we'll have to use a different strategy than that used by Shape Up. We might define a search param on url to handle that. Suggestion:

?example=1

So the value might be the index of the example. Doing so, when the component <p-external-component-examples-list> gets rendered, it looks for the search param and, if it finds that, it scrolls the window to the specific example. It' important to notice that on mobile we'll have to add an offset relating the Topbar's height.

What are your thoughts?