docs(en): merge Recoil/docs into Recoil/docs @ fbe449bc

[docschina-bot]

此 PR 自动生成。

合并 facebookexperimental/Recoil 的修改至本仓库（@ fbe449b）

以下文件存在冲突，可能需要重新翻译：

• docs/docs/api-reference/core/Loadable.md
• docs/docs/api-reference/core/RecoilRoot.md
• docs/docs/api-reference/core/Snapshot.md
• docs/docs/api-reference/core/atom.md
• docs/docs/api-reference/core/selector.md
• docs/docs/api-reference/core/useGetRecoilValueInfo.md
• docs/docs/api-reference/core/useRecoilCallback.md
• docs/docs/api-reference/core/useRecoilSnapshot.md
• docs/docs/api-reference/core/useRecoilState.md
• docs/docs/api-reference/core/useRecoilValue.md
• docs/docs/api-reference/core/useRecoilValueLoadable.md
• docs/docs/api-reference/utils/atomFamily.md
• docs/docs/api-reference/utils/selectorFamily.md
• docs/docs/basic-tutorial/intro.md
• docs/docs/basic-tutorial/selectors.md
• docs/docs/guides/asynchronous-data-queries.md
• docs/docs/guides/atom-effects.md
• docs/docs/guides/testing.md
• docs/docs/introduction/core-concepts.md
• docs/docs/introduction/installation.md
• docs/yarn.lock

请解决所有冲突后提交到此 pull request，可直接在 Github 修改、切换到 sync-fbe449bc 分支进行修改或者使用 Github Desktop 拉取此 pr 修改并提交。

禁止使用 Squash Merge 来合并此 Pull Request！

使用该操作会导致上游仓库的内容丢失，并致使下一次合并产生冲突。