Apply suggestions from code review

Author: RalfJung

CONTRIBUTING.md

@@ -160,7 +160,7 @@ evaluation error was originally raised.
 
 #### Tracing
 
-You can generate a Chrome trace file from a Miri execution by passing `--features=tracing` during
+You can generate a Chrome trace file from a Miri execution by passing `--features=tracing` during the
 build and then setting `MIRI_TRACING=1` when running Miri. This will generate a `.json` file that
 you can visualize in [Perfetto](https://ui.perfetto.dev/). For example:
 

src/bin/log/tracing_chrome.rs

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
-// SPDX-FileCopyrightText: 2020 Thoren Paulson
+// SPDX-FileCopyrightText: Copyright (c) 2020 Thoren Paulson
 //! This file is taken unmodified from the following link, except for file attributes and
-//! `extern crate` at the top. It is licensed under MIT.
+//! `extern crate` at the top.
 //! https://github.com/thoren-d/tracing-chrome/blob/7e2625ab4aeeef2f0ef9bde9d6258dd181c04472/src/lib.rs
 //! Depending on the tracing-chrome crate from crates.io is unfortunately not possible, since it
 //! depends on `tracing_core` which conflicts with rustc_private's `tracing_core` (meaning it would