Apply some light edits to the introduction

This is just some light editing. I expect that this chapter will have
larger edits in the future, but I want to defer that till later.

Author: ehuss

contributor-guide/src/introduction.md

@@ -1,44 +1,42 @@
 # Introduction
 
-Thank you for your interest in contributing to the Rust Reference!
+Thank you for your interest in contributing to the Rust Reference! This guide provides an overview of how to contribute to the Reference, and serves as a guide for editors and reviewers.
 
-There are a few ways of helping with the reference: critiquing the reference, editing the reference, fixing incorrect information, adding examples and glossary entries, and documenting new or otherwise undocumented features in Rust.
+There are a few ways of helping with the Reference: critiquing the Reference, editing the Reference, fixing incorrect information, adding examples and glossary entries, and documenting new or otherwise undocumented features in Rust.
 
-For a while, the Reference was basically ignored, and Rust continued gaining new features or changing old ones. It was also basically the introduction document before the first edition of the Rust book, and constantly in flux from the huge churn of the language design before v1.0.0. So there's a lot that's wrong, too teachy for people who should have basic understanding of Rust, or is too shallow for the Reference. As such, we have the warning saying there's work that needs to be done. Eventually, we plan to make sure everything is well documented enough that we can remove the warning.
-
-It is encouraged for you to read the [introduction] to familiarize yourself with the kind of content the reference is expected to contain and the conventions it uses. Also, the [Authoring Guide] provides more detailed guidelines for formatting and content.
+It is encouraged for you to read the [introduction] of the Reference to familiarize yourself with the kind of content the Reference is expected to contain and the conventions it uses.
 
 ## Critiquing the Reference
 
-This is the easiest way to contribute. Basically, as you read the reference, if you find something confusing, incorrect, or missing, then you can file an issue against the reference explaining your concerns.
+This is the easiest way to contribute. Basically, as you read the Reference, if you find something confusing, incorrect, or missing, then you can file an issue against the Reference explaining your concerns.
 
 ## Editing the Reference
 
-Typos and incorrect links get through from time to time. Should you find them, we welcome PRs to fix them. Additionally, larger editing jobs that help remove the number of parentheticals, remove comma splices, italicize term definitions and other similar tasks are helpful.
+Typos and incorrect links get through from time to time. Should you find them, we welcome PRs to fix them.
 
 ## Adding examples and glossary entries
 
 Examples are great. Many people will only read examples and ignore the prose. Ideally, every facet of every feature will have an example.
 
-Likewise, the reference has a glossary. It doesn't need to explain every facet of every feature nor contain every definition, but it does need to be expanded upon. Ideally entries in the glossary link to the associated documentation.
+Likewise, the Reference has a glossary. It doesn't need to explain every facet of every feature nor contain every definition, but it does need to be expanded upon. Ideally entries in the glossary link to the associated documentation.
 
 ## Adding documentation
 
 There are a lot of features that are not documented at all or are documented poorly. This is the hardest, but definitely most valuable. Pick an unassigned issue from the [issue tracker], and write about it.
 
-While writing, you may find it handy to have a [playpen] open to test out what you are documenting.
+While writing, you may find it handy to have a [playground] open to test out what you are documenting.
 
 Feel free to take information from the standard library and Rustonomicon as appropriate.
 
-Note that we don't write documentation for purely library features such as threads and IO and we don't write about Rust in the future. Documentation is written as if the current stable release of Rust is the last release. The `master` branch of the reference corresponds to what is **stable** on the `master` branch ("nightly") of [rust-lang/rust]. If you want to write about Rust in the future, you want [the Unstable book][unstable].
+Note that we don't write documentation for purely library features such as threads and IO and we don't write about Rust in the future. Documentation is written as if the current stable release of Rust is the last release. The `master` branch of the Reference corresponds to what is **stable** on the `master` branch ("nightly") of [rust-lang/rust]. If you want to write about Rust in the future, you want [the Unstable book][unstable].
 
 ## Stabilization
 
-When something that alters the language is stabilized, an issue should be opened on the reference [issue tracker] to track the documentation process. This should include links to any relevant information, such as the stabilization PR, the RFC, the tracking issue, and anything else that would be helpful for writing the documentation.
+When something that alters the language is stabilized, an issue should be opened on the Reference [issue tracker] to track the documentation process. This should include links to any relevant information, such as the stabilization PR, the RFC, the tracking issue, and anything else that would be helpful for writing the documentation.
 
 [Authoring Guide]: docs/authoring.md
 [introduction]: src/introduction.md
 [issue tracker]: https://github.com/rust-lang/reference/issues
-[playpen]: https://play.rust-lang.org/
+[playground]: https://play.rust-lang.org/
 [rust-lang/rust]: https://github.com/rust-lang/rust/
 [unstable]: https://doc.rust-lang.org/nightly/unstable-book/