fix: set palette from colors attribute on init

[sakithb]

#389

[sakithb]

The colors attribute does not work when set in the markup and only takes effect when it is changed programmatically. This pr let's the user set the attribute in the markup and set the palette.

[sakithb]

Update docs:

[supun-io]

@Nadil-K what do you think?

On the one hand, I think we should not integrate external systems directly within the embed.

On the other hand, Hyvor Blogs is our own platform. It generally makes sense to have something like this in HP.

Initially, my thought was to handle this at the installation time, by giving the user a code snippet with a code like this included

[Nadil-K]

This doesn't look nice to me. HB is indeed our own product, but listening to an HB event within HP is too specific.

I like the idea of handling this at the installation time with a code snippet.