Single patch downgrade of docfx (net effect with last commit is a single patch upgrade).

Author: dan-terry-antithesis

.config/dotnet-tools.json

@@ -10,7 +10,7 @@
       "rollForward": false
     },
     "docfx": {
-      "version": "2.78.5",
+      "version": "2.78.4",
       "commands": [
         "docfx"
       ],