add Rust Testing workshop

Author: marcoow

draft/2025-01-08-this-week-in-rust.md

@@ -190,6 +190,8 @@ Rusty Events between 2025-01-08 - 2025-02-05 🦀
     * [**Mid-month Rustful**](https://www.meetup.com/rustdc/events/rdhhptyhccbcc)
 * 2025-01-22 | Virtual (Rotterdam, NL) | [Bevy Game Development](https://www.meetup.com/bevy-game-development/events/)
     * [**Bevy Meetup #8**](https://www.meetup.com/bevy-game-development/events/305111151)
+* 2025-01-23 & 2025-01-24 | Virtual | [Mainmatter Rust Workshop](https://ti.to/mainmatter/)
+    * [**Remote Workshop: Testing for Rust projects – going beyond the basics**](https://ti.to/mainmatter/rust-testing-jan-2025)
 * 2025-01-26 | Virtual (Tel Aviv-Yafo, IL) | [Rust 🦀 TLV](https://www.meetup.com/rust-tlv/events/)
     * [**Rust and embedded programming with Leon Vak (online in Hebrew)**](https://www.meetup.com/rust-tlv/events/304971264)