[docgen] Update doc/neogen.txt

skip-checks: true

Author: github-actions

doc/neogen.txt

@@ -148,7 +148,7 @@ For example, if you are inside a function, and called `generate({ type = "func"
 Neogen will go until the start of the function and start annotating for you.
 
 Parameters ~
-{opts} `(table)` Optional configs to change default behaviour of generation.
+{opts} `(optional)` `(table)` Optional configs to change default behaviour of generation.
  - {opts.type} `(string, default: "any")` Which type we are trying to use for generating annotations.
    Currently supported: `any`, `func`, `class`, `type`, `file`
  - {opts.annotation_convention} `(table)` convention to use for generating annotations.