Configure prettier.ignorePath for Visual Studio Code (#80)

In our monorepo we defined seprate prettier configurations for the
modules and the root directory. VS Code has problems resolving the
prettier ignore configuration, and reads root's file by default, which
ignores the modules from formatting.
Here we specify no file to use with prettier ignore configuration so VS
Code can still work.

.vscode/settings.json

@@ -1,3 +1,4 @@
 {
-  "eslint.workingDirectories": [{ "mode": "auto" }]
+  "eslint.workingDirectories": [{ "mode": "auto" }],
+  "prettier.ignorePath": ""
 }