documentation: Add article and talk by hoverbear (#2679)

Author: Hoverbear

README.md

@@ -460,14 +460,17 @@ Tracing.
 * [Diagnostics with Tracing][tokio-blog-2019-08] on the Tokio blog, August 2019
 * [Production-Grade Logging in Rust Applications][production-logging-2020], November 2020
 * [Custom Logging in Rust using `tracing` and `tracing-subscriber`, part 1][custom-logging-part-1] and [part 2][custom-logging-part-2], October 2021
+* [Instrumenting Axum projects][detsys-blog-2023-08], August 2023
 
 [tokio-blog-2019-08]: https://tokio.rs/blog/2019-08-tracing/
+[detsys-blog-2023-08]: https://determinate.systems/posts/instrumenting-axum
 
 #### Talks
 
 * [Bay Area Rust Meetup talk and Q&A][bay-rust-2019-03], March 2019
 * [RustConf 2019 talk][rust-conf-2019-08-video] and [slides][rust-conf-2019-08-slides], August 2019
 * [Are we observable yet? @ RustyDays talk][rusty-days-2020-08-video] and [slides][rusty-days-2020-08-slides], August 2020
+* [Crabs with instruments!][tremorcon-2021-09], September 2021
 
 [bay-rust-2019-03]: https://www.youtube.com/watch?v=j_kXRg3zlec
 [rust-conf-2019-08-video]: https://www.youtube.com/watch?v=JjItsfqFIdo
@@ -477,6 +480,7 @@ Tracing.
 [production-logging-2020]: https://medium.com/better-programming/production-grade-logging-in-rust-applications-2c7fffd108a6
 [custom-logging-part-1]: https://burgers.io/custom-logging-in-rust-using-tracing
 [custom-logging-part-2]: https://burgers.io/custom-logging-in-rust-using-tracing-part-2
+[tremorcon-2021-09]: https://www.youtube.com/watch?v=ZC7fyqshun8
 
 Help us expand this list! If you've written or spoken about Tracing, or
 know of resources that aren't listed, please open a pull request adding them.