[l10n] Add Czech and Slovak locales

[char0n]

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

[mui-pr-bot]

No bundle size changes comparing 6ced014...ca459a1

Generated by 🚫 dangerJS against ca459a1

[char0n]

@honzajavorek can you pls have a quick look at this to verify my Czech skills ? ;]

[mbrookes]

On hold Pending Czech review from @honzajavorek.

[oliviertassinari]

@mbrookes The alternative is to release it, if the translations are wrong, and if it's important, somebody will come and fix it?

[char0n]

I'm native speaker of both Slovak and Czech languages. So I'd say it's pretty safe to merge this PR. Just wanted to have somebody else like @honzajavorek have a look at this to verify I haven't done any spelling mistake.

[honzajavorek]

I plan to look at it this afternoon, but I don’t expect to find anything more than a random typo. Vladimir is 95% native Czech :)

…

On Tue, 17 Dec 2019 at 08:11, Vladimir Gorej ***@***.***> wrote: I'm native speaker of both Slovak and Czech languages. So I'd say it's pretty safe to merge this PR. Just wanted to have somebody else like @honzajavorek <https://github.com/honzajavorek> have a look at this to verify I haven't done any spelling mistake. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#18876>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACFGMO4A2LYBNVLSKBXG73QZB3SXANCNFSM4J3KIJNQ> .

[honzajavorek]

I think "hvězdička" would be preferred over "hvězda" in the context of rating.

Also I spotted an extra whitespace, I'm not sure whether that is intended or not, but I don't see it in the other translations so I guess it's just a typo.

Otherwise 👍

[honzajavorek]

⭐️ ⭐️ ⭐️ ⭐️ ⭐️

[oliviertassinari]

Thank you guys 🤗