[docs] Add TypeScript demos for Dividers

[eluchsinger]

• I have followed (at least) the PR section of the contributing guide.

Pull Request for the TypeScript conversion of the Dividers demo.

Edit @eps1lon:
Once #15040 is merged we need to rebase this with next before merge.

[eluchsinger]

I posted a few comments that should be resolved before merging.

[joshwooding]

I posted a few comments that should be resolved before merging.

Have you submitted the comments? I can’t see any.

[eluchsinger]

I posted a few comments that should be resolved before merging.

Have you submitted the comments? I can’t see any.

@joshwooding Fixed that one!

[mui-pr-bot]

No bundle size changes comparing 60e0c31...5757321

Generated by 🚫 dangerJS against 5757321

[oliviertassinari]

@StevenGodin has contributed a pull request converting the same components in #15040.

[oliviertassinari]

I'm proposing the following plan of action:

1. We merge [Divider] Enable component generic props #15040 to fix the Divider TypeScript definitions.
2. We rebase this pull request on top of it.
3. We merge this pull request.

[oliviertassinari]

@eluchsinger Rebased, well done!

[hexetia]

We have a little error here, the "& WithTheme" declaration , the withStyles HOC don't automatically pass the theme as prop, so we are wrongly here, that type declaration should be

type Props = WithStyles<typeof styles>;

[joshwooding]

We have a little error here, the "& WithTheme" declaration , the withStyles HOC don't automatically pass the theme as prop, so we are wrongly here, that type declaration should be

type Props = WithStyles<typeof styles>;

@saculbr Whoops! Nice spot, do you want to create a PR?