Add mkdocs build script to VS Code tasks list

Author: nathancarter

.vscode/tasks.json

@@ -3,6 +3,12 @@
     // for the documentation about the tasks.json format
     "version": "2.0.0",
     "tasks": [
+        {
+            "label": "Rebuild site using MkDocs",
+            "type": "shell",
+            "command": "mkdocs build",
+            "problemMatcher": [],
+        },
         {
             "label": "Rebuild all source code documentation folders",
             "type": "shell",