Fix link to edition team

rust-lang/team#546 broke the link.

Author: m-ou-se

posts/inside-rust/2021-03-04-planning-rust-2021.md

@@ -2,7 +2,7 @@
 layout: post
 title: "Planning the Rust 2021 Edition"
 author: Ryan Levick
-team: The Rust 2021 Edition Working Group <https://www.rust-lang.org/governance/teams/lang#project-edition-2021>
+team: The Rust 2021 Edition Working Group <https://www.rust-lang.org/governance/teams/core#project-edition-2021>
 ---
 
 The Rust 2021 Edition working group is happy to announce that the next edition of Rust, Rust 2021, is scheduled for release later this year. While the [RFC](https://github.com/rust-lang/rfcs/pull/3085) formally introducing this edition is still open, we expect it to be merged soon. Planning and preparation have already begun, and we're on schedule!