docs: add tracing-logfmt to related crates (#2163)

Adds tracing-logfmt crate to the related crates section

Author: fredr

README.md

@@ -402,6 +402,7 @@ are not maintained by the `tokio` project. These include:
 - [`tracing-forest`] provides a subscriber that preserves contextual coherence by 
   grouping together logs from the same spans during writing.
 - [`tracing-loki`] provides a layer for shipping logs to [Grafana Loki].
+- [`tracing-logfmt`] provides a layer that formats events and spans into the logfmt format.
 
 (if you're the maintainer of a `tracing` ecosystem crate not in this list,
 please let us know!)
@@ -439,6 +440,7 @@ please let us know!)
 [`tracing-forest`]: https://crates.io/crates/tracing-forest
 [`tracing-loki`]: https://crates.io/crates/tracing-loki
 [Grafana Loki]: https://grafana.com/oss/loki/
+[`tracing-logfmt`]: https://crates.io/crates/tracing-logfmt
 
 **Note:** that some of the ecosystem crates are currently unreleased and
 undergoing active development. They may be less stable than `tracing` and

tracing/README.md

@@ -395,6 +395,7 @@ maintained by the `tokio` project. These include:
   framework for validating the behavior of `tracing` spans.
 - [`sentry-tracing`] provides a layer for reporting events and traces to [Sentry].
 - [`tracing-loki`] provides a layer for shipping logs to [Grafana Loki].
+- [`tracing-logfmt`] provides a layer that formats events and spans into the logfmt format.
 
 If you're the maintainer of a `tracing` ecosystem crate not listed above,
 please let us know! We'd love to add your project to the list!
@@ -424,6 +425,7 @@ please let us know! We'd love to add your project to the list!
 [Sentry]: https://sentry.io/welcome/
 [`tracing-loki`]: https://crates.io/crates/tracing-loki
 [Grafana Loki]: https://grafana.com/oss/loki/
+[`tracing-logfmt`]: https://crates.io/crates/tracing-logfmt
 
 **Note:** that some of the ecosystem crates are currently unreleased and
 undergoing active development. They may be less stable than `tracing` and

tracing/src/lib.rs

@@ -743,6 +743,7 @@
 //!  - [`tracing-forest`] provides a subscriber that preserves contextual coherence by
 //!    grouping together logs from the same spans during writing.
 //!  - [`tracing-loki`] provides a layer for shipping logs to [Grafana Loki].
+//!  - [`tracing-logfmt`] provides a layer that formats events and spans into the logfmt format.
 //!
 //! If you're the maintainer of a `tracing` ecosystem crate not listed above,
 //! please let us know! We'd love to add your project to the list!
@@ -779,6 +780,7 @@
 //! [`tracing-forest`]: https://crates.io/crates/tracing-forest
 //! [`tracing-loki`]: https://crates.io/crates/tracing-loki
 //! [Grafana Loki]: https://grafana.com/oss/loki/
+//! [`tracing-logfmt`]: https://crates.io/crates/tracing-logfmt
 //!
 //! <pre class="ignore" style="white-space:normal;font:inherit;">
 //!     <strong>Note</strong>: Some of these ecosystem crates are currently