Move "Showcase" category under "Projects"

This will be a more logical location for the "Showcase" category than the previous location under "Community".

Author: per1234

content/categories/order.md

@@ -22,6 +22,7 @@
   - Programming
   - Networking, Protocols, and Devices
   - Interfacing w/ Software on the Computer
+  - Showcase
   - Libraries
   - Emergency Response: Covid-19 Projects
 - Official Hardware
@@ -111,7 +112,6 @@
   - Website and Forum
   - Suggestions for the Arduino Project
   - Education
-  - Showcase
   - Project Hub
   - Groups and Events
   - Bar Sport

content/categories/community/showcase/README.md renamed to content/categories/projects/showcase/README.md

@@ -8,4 +8,4 @@
 
 ## Published At
 
-https://forum.arduino.cc/c/community/showcase/45
+https://forum.arduino.cc/c/projects/showcase/45