Add --omd-aligned flag for column-padded markdown output (#2057)

Adds a new Markdown-only flag --omd-aligned (alias --omarkdown-aligned)
that left-justifies cells and pads each column to a uniform width.
The rendered table is unaffected; the goal is readability of the raw
markdown source. The flag implies --omd, so users do not need to pass
both.

Implementation batches records by schema (like pprint), computes max
column widths, then emits header / separator / data rows with bars
vertically aligned. Default markdown writer behavior is unchanged.

pkg/cli/option_parse.go

@@ -117,6 +117,7 @@ var FLAG_TABLE = FlagTable{
 		&CSVTSVOnlyFlagSection,
 		&JSONOnlyFlagSection,
 		&PPRINTOnlyFlagSection,
+		&MarkdownOnlyFlagSection,
 		&DKVPOnlyFlagSection,
 		&CompressedDataFlagSection,
 		&CommentsInDataFlagSection,
@@ -582,6 +583,35 @@ var PPRINTOnlyFlagSection = FlagSection{
 	},
 }
 
+// MARKDOWN-ONLY FLAGS
+
+func MarkdownOnlyPrintInfo() {
+	fmt.Println("These are flags which are applicable to markdown-tabular format.")
+}
+
+func init() { MarkdownOnlyFlagSection.Sort() }
+
+var MarkdownOnlyFlagSection = FlagSection{
+	name:        "Markdown-only flags",
+	infoPrinter: MarkdownOnlyPrintInfo,
+	flags: []Flag{
+
+		{
+			name:     "--omd-aligned",
+			altNames: []string{"--omarkdown-aligned"},
+			help: "For markdown-tabular output, left-justify cells and pad each " +
+				"column to a uniform width, making the raw markdown source easier " +
+				"to read and maintain. (The rendered table is unaffected.) Implies " +
+				"--omd, so you do not need to also pass --omd.",
+			parser: func(args []string, argc int, pargi *int, options *TOptions) {
+				options.WriterOptions.OutputFileFormat = "markdown"
+				options.WriterOptions.MarkdownAlignedOutput = true
+				*pargi += 1
+			},
+		},
+	},
+}
+
 // DKVP-ONLY FLAGS
 
 func DKVPOnlyPrintInfo() {

pkg/cli/option_types.go

@@ -101,6 +101,7 @@ type TWriterOptions struct {
 	BarredUseUnicode         bool
 	RightAlignedPPRINTOutput bool
 	RightAlignedXTABOutput   bool
+	MarkdownAlignedOutput    bool
 
 	// JSON output: --jlistwrap on, --jvstack on
 	// JSON Lines output: --jlistwrap off, --jvstack off