doc: Fix markdown links in lts.md

docs/lts.md

@@ -1,12 +1,14 @@
 ## Long Term Support
 <a id="lts"></a>
 
-Pino's Long Term Support (LTS) is tied to the
-[Node.js LTS policy](https://github.com/nodejs/Release). Major versions of
-Pino, "X" releases in X.Y.Z of [semantic versioning][semver] nomenclature, will
+Pino's Long Term Support (LTS) is tied to the [Node.js LTS policy].
+Major versions of Pino, "X" releases in X.Y.Z of [semantic versioning] nomenclature, will
 be issued as close as possible to the release of a new major LTS release of
 Node.js (subject to the Pino maintainers's capacity). Pino makes no guarantees
 as to the operability of the library on unsupported releases of Node.js.
 
 Pino will not remove support for a deprecated Node.js release via a minor,
 or patch, release of Pino.
+
+[semantic versioning]: https://semver.org/
+[Node.js LTS policy]: https://github.com/nodejs/Release