VS Code tasks.json fixed to build the entire solution. X-unit test settings adjusted for better performance.

Recyclable.CollectionsTests/xunit.runner.json

@@ -0,0 +1,6 @@
+{
+	"$schema": "https://xunit.net/schema/current/xunit.runner.schema.json",
+	"methodDisplay": "method",
+	"parallelizeTestCollections": true,
+	"preEnumerateTheories": false
+}