Minor README Updates

[NilaierMusic]

中文:

我对主 README.md 文件做了一些小改动,让它更方便一些:

• 将相对文件链接改为直接链接,这样 Thunderstore 上的用户就可以直接点击它们,进入这些翻译文件的相应页面,而不是遇到错误页面。
• 修复了 Language 中的一个小错别字。
• 为贡献者添加了超链接,为了方便和美观。

此外,我还在 README-ru.md 中添加了一些内容,以更加符合主文件:

• 为 Features 添加了更多描述性的部分。
• 添加了扩展的贡献部分。
• 也匹配了此文件中之前的添加内容。

English:

Some small changes i did to make main README.md file a bit more convenient:

• Changed relative file links to direct ones, so people on Thunderstore can actually click on them and get on the respective pages for these translation files instead of being met with the error page.
• Fixed a little typo in Language
• Added hyperlinks to contributors, just for convenience and stylistic sake.

Also, added some stuff to README-ru.md to match up more closely to the main file:

• Added more descriptive sections for Features
• Added extended contribution section.
• Matched previous additions in this file too.

[chuxiaaaa]

Is everything ready?