Removed header output relabeling and added column filtering with label handling.

src/index.ts

@@ -3,10 +3,11 @@
 export { toMarkdownTable } from "./markdown.ts";
 export {
   outputFiltered,
-  parseHeaderSpec,
+  parseColumnSpec,
   normalizeOutputFormat,
   readJsonFromStdin,
   readCsvFromStdin,
   renderOutput,
+  renderCliOutput,
 } from "./cli/utils.ts";
 export { getConfigDir, getConfig } from "./config/index.ts";