fix(docs): fixed small errors

[0xflotus]

Please read and mark the following check list before creating a pull request:

• I read and followed the CONTRIBUTING.md guide.
• I read and followed the New Feature Checklist guide.

Short description of what this resolves:

I only fixed some small errors in the docs. Some of the links are broken, this should be fixed in the future.

[nnixaa]

Thanks @0xflotus! Could you let me know what links are broken?

[0xflotus]

e.g.