docs: updated README to show new output customization

README.md

···
 ```lua
 {
   'https://tangled.org/bpavuk.neocities.org/jj-log.nvim',
-  opts = {},
+  opts = {
+    -- these are default options 
+    out_waiting = "...",
+    out_no_jj_repo = "~no_jj_repo~",
+    out_no_desc = "~no_desc~",
+    max_desc_length = 47, -- including truncation dots, that's 50
+  },
 }
 ```