add post about 1.48.0 pre-release testing

Author: pietroalbini

posts/inside-rust/2020-11-16-1.48.0-prerelease.md

@@ -0,0 +1,22 @@
+---
+layout: post
+title: "1.48.0 pre-release testing"
+author: Pietro Albini
+team: The Release Team <https://www.rust-lang.org/governance/teams/release>
+---
+
+The 1.48.0 pre-release is ready for testing. The release is scheduled for this
+Thursday, November 19th. [Release notes can be found here.][relnotes]
+
+You can try it out locally by running:
+
+```plain
+RUSTUP_DIST_SERVER=https://dev-static.rust-lang.org rustup update stable
+```
+
+The index is <https://dev-static.rust-lang.org/dist/2020-11-16/index.html>. You
+can leave feedback on the [internals thread][internals].
+
+[#76980]: https://github.com/rust-lang/rust/issues/76980
+[relnotes]: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1480-2020-11-19
+[internals]: https://internals.rust-lang.org/t/rust-1-48-0-pre-release-testing/13401