Add erlfmt as a project_plugin
diff --git a/rebar.config b/rebar.config
index b4d2930..e526511 100644
--- a/rebar.config
+++ b/rebar.config
@@ -2,6 +2,10 @@
     pc
 ]}.
 
+{project_plugins, [
+    erlfmt
+]}.
+
 {provider_hooks, [
     {pre, [
         {compile, {pc, compile}},