Add local switch to .gitignore

Gary Trakhman · gtrak · commit cf2f3c4136ae · 2022-05-31T12:21:31.000-04:00
diff --git a/.gitignore b/.gitignore
@@ -5,3 +5,4 @@ _esy
 .merlin
 esy.lock
 node_modules
+_opam
