Fix broken link to shure blog (#163)

Existing link was a 404

Author: jacobparis

content/instructor/screencasting/audio-equipment/index.mdx

@@ -47,7 +47,7 @@ The boom is a stand for your mic. Booms can range in size and shape. (Action mov
 
 ![photo of microphone](./images/audio-setup/mic.jpg)
 
-Obviously an important piece of equipment! The **Shure BETA 87a** is a [supercardioid](http://blog.shure.com/multi-pattern-microphones-what-where-and-how/) mic, which refers to how it picks up sound: It’s forgiving and blocks out ambient noise.
+Obviously an important piece of equipment! The **Shure BETA 87a** is a [supercardioid](https://www.shure.com/en-US/performance-production/louder/multi-pattern-microphones-what-where-and-how) mic, which refers to how it picks up sound: It’s forgiving and blocks out ambient noise.
 
 You can go crazy with mics, spending a huge amount for a smidge better sound quality. You might not use this mic to record a #1 banger, but it still fits into the "sounds very good" column. 👍
 
@@ -99,4 +99,4 @@ Ta-da! You’re ready to record.
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