Add markdown support.

Don't create Strings to convert to bytes later, just serialize directly
to bytes in the first place

src/main.rs

@@ -152,6 +152,13 @@ fn main() {
                 .value_name("FILE")
                 .help("Export the timing results as JSON to the given FILE."),
         )
+        .arg(
+            Arg::with_name("export-md")
+                .long("export-md")
+                .takes_value(true)
+                .value_name("FILE")
+                .help("Export the timing results to a markdown table in the given file"),
+        )
         .help_message("Print this help message.")
         .version_message("Show version information.")
         .get_matches();
@@ -188,6 +195,9 @@ fn main() {
     if let Some(filename) = matches.value_of("export-csv") {
         export_manager.add_exporter(ExportType::Csv, filename);
     }
+    if let Some(filename) = matches.value_of("export-md") {
+        export_manager.add_exporter(ExportType::Markdown, filename);
+    }
 
     // We default Windows to NoColor if full had been specified.
     if cfg!(windows) && options.output_style == OutputStyleOption::Full {