use nvim-foldsigns

because the built-in foldsigns are too cramped together

.config/nvim/lua/plugins/foldsigns.lua

@@ -0,0 +1,12 @@
+return {
+   'yaocccc/nvim-foldsign',
+   event = { 'BufReadPre', 'BufNewFile' },
+   opts = {
+      offset = -2,
+      foldsigns = {
+         open = '',
+         close = '',
+         seps = { '' },
+      },
+   },
+}