docs: remove hard coded version link from readme (#2208)

Motivation:
When a user clicks they they may accidentally get an old version of the
crate. Its also out of sync with the current main readme.

Solution:
removed the hard coded links

Author: cgbur

tracing/README.md

@@ -16,9 +16,9 @@ Application-level tracing for Rust.
 [Documentation][docs-url] | [Chat][discord-url]
 
 [crates-badge]: https://img.shields.io/crates/v/tracing.svg
-[crates-url]: https://crates.io/crates/tracing/0.1.35
+[crates-url]: https://crates.io/crates/tracing
 [docs-badge]: https://docs.rs/tracing/badge.svg
-[docs-url]: https://docs.rs/tracing/0.1.35
+[docs-url]: https://docs.rs/tracing
 [docs-master-badge]: https://img.shields.io/badge/docs-master-blue
 [docs-master-url]: https://tracing-rs.netlify.com/tracing
 [mit-badge]: https://img.shields.io/badge/license-MIT-blue.svg