fix: link frappe node_modules to make Website Theme work (#702)

* fix: link frappe node_modules to make Website Theme work

* Add website theme test

* Fix failing test

Co-authored-by: Lev Vereshchagin <mail@vrslev.com>

tests/_check_website_theme.py

@@ -0,0 +1,17 @@
+import frappe
+
+
+def check_website_theme():
+    doc = frappe.new_doc("Website Theme")
+    doc.theme = "test theme"
+    doc.insert()
+
+
+def main() -> int:
+    frappe.connect(site="tests")
+    check_website_theme()
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())