Edit subsection editors

[pengyuejiang]

Description

In this chapter, some concepts were mentioned before they are properly introduced, for instance, "race condition." This confused me a lot when I was a student. So I included hyper-references to these concepts later in book in case the students want to investigate. In addition, I enriched the contents for the subsection "Editor" regarding how to get started with vim, as I believe that is an important tool, and the current description for it is not too comprehensive. Finally, I fixed some minor typo.

Checklist

Before you create this PR confirm that it meets all requirements listed below by checking the relevant checkboxes ([x]). This will ensure a smooth and quick review process.

• [x] I updated AUTHORS with my name and email.
• [x] I read the Contributor Guide and followed the process outlined there for submitting PRs.
• [x] My PR builds for all changed/updated/fixed behaviors (See [Contributor Guide]).
• [ ] I updated/added relevant documentation.
• [x] The title of the PR is descriptive and doesn't have [WIP]
• [ ] I updated CHANGELOG.md to add a description of the change.
• [x] I am willing to follow-up on review comments in a timely manner.

Breaking Change

Does this cause any new material not previously covered in the course to be required?

• [ ] Yes, this is a breaking change (please indicate a breaking change in CHANGELOG.md).
• [x] No, this is not a breaking change.

[ezhang887]

Also, seems like the new links aren't working correctly for the wiki version (from a local build I did):

Here's what the generated markdown looks like:

1.  \! If a value is stored in two different processor caches, then that
    value should be accessed by a single thread.

Why do we mention this? Because it is important that although you are
going to be doing most of this class in C, that this is what the code is
translated into. Serious implications arise for and atomic operations.

[pengyuejiang]

Alright, I have made changes according to the comments. As for hyper reference, I will leave that for now until a nice solution can be thought of. Honestly I don't know how to do it.