Add a workplace snippets file

* `nhostHttpProxy` snippet contains easy HTTP proxy setup.

.vscode/helpers.code-snippets

@@ -0,0 +1,19 @@
+{
+	// Place your nhost-dart workspace snippets here. Each snippet is defined under a snippet name and has a scope, prefix, body and
+	// description. Add comma separated ids of the languages where the snippet is applicable in the scope field. If scope
+	// is left empty or omitted, the snippet gets applied to all languages. The prefix is what is
+	// used to trigger the snippet and the body will be expanded and inserted. Possible variables are:
+	// $1, $2 for tab stops, $0 for the final cursor position, and ${1:label}, ${2:another} for placeholders.
+	// Placeholders with the same ids are connected.
+	// Example:
+	"Client HTTP proxy": {
+		"scope": "dart",
+		"prefix": "nhostHttpProxy",
+		"body": [
+			"httpClientOverride: IOClient(",
+			"  HttpClient()..findProxy = (_) => 'PROXY localhost:8888; DIRECT',",
+			"),",
+		],
+		"description": "An httpClientOverride for NhostClient that configures HTTP proxying"
+	}
+}