Add extension https://github.com/sargedev/betterarrays

Fixes #143

Author: UnsignedArduino

content/extensions/069-sargedev---betterarrays.md

@@ -0,0 +1,9 @@
+---
+repo: "https://github.com/sargedev/betterarrays"
+links:
+  - title: Forum post
+    url: >-
+      https://forum.makecode.com/t/extension-betterarrays-60-useful-array-blocks/29154?u=unsignedarduino
+---
+
+From the creator of the amazing `bettersettings` extension, @sargedev graces us with `betterarrays` - adding **over 60 blocks** to the `Arrays` category in the toolbox, (or the `arrays` namespace in JavaScript) designed to help you manipulate arrays in MakeCode Arcade, reducing the redundancy in your program of manually implementing these methods yourself. Check out the forum post for extremely detailed documentation. (scroll down as blocks have been added)