test_generate_cli_reference: fixup to 52c415e, remove mysterious comment

If I can't tell what this comment means, probably nobody else can
either.

I think it might be a copy-paste error from whatever docs I copied the
initial version of the config from.

cli/tests/test_generate_md_cli_help.rs

@@ -27,7 +27,7 @@ fn test_generate_markdown_docs_in_docs_dir() {
     let mut markdown_help = PREAMBLE.to_string();
     markdown_help
         .push_str(&test_env.jj_cmd_success(test_env.env_root(), &["util", "markdown-help"]));
-    // Validate partial snapshot, redacting any lines nested 2+ indent levels.
+
     insta::with_settings!({
         snapshot_path => ".",
         snapshot_suffix => ".md",