Change structure to have docs folder on highest level

[franzihei]

I believe this repo structure needs to be changed for the translation PR bot to work, correct @o-lenczyk @cameel?

[cameel]

Yes. We'll need to convert it.

1. We need to determine which specific revision of the main repo was used as a base of the translation. This needs to be done carefully because if we include commits with text that was not translated, bot will assume it was translated. On the other hand, if we miss some commits that were translated, the bot will overwrite them with English text in the PR. The latter is easier to spot and correct for the translator so I'd err on the side of going a bit farther into the past if unsure.
2. Once we know the exact revision, we can fork the Solidity repo at that commit.
3. Then we need to copy over files from this repo on top of that. Then commit them.
4. Then we can run the bot. Its first PR will be a big one and contain everything that happened in the Solidity repo between that chosen commit an now.