Render all documentation

The following changes the documentation command to use io.Writer
instead of the bufio.Writer. This means that we can then just use
the stdout for writing the documentation output. As the bufio buffer
is actually rather small, only 4096 bytes long. We clearly don't
blow past that during the individual files, but we do when dumping
out the documentation.

documentation.go

@@ -7,6 +7,7 @@ import (
 	"bufio"
 	"errors"
 	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 	"sort"
@@ -102,7 +103,7 @@ func (c *documentationCommand) Run(ctx *Context) error {
 
 // dumpOneFile is invoked when the output is contained in a single output
 func (c *documentationCommand) dumpOneFile(ctx *Context) error {
-	var writer *bufio.Writer
+	var writer io.Writer
 	if c.out != "" {
 		_, err := os.Stat(c.out)
 		if err != nil {
@@ -116,9 +117,9 @@ func (c *documentationCommand) dumpOneFile(ctx *Context) error {
 			return err
 		}
 		defer f.Close()
-		writer = bufio.NewWriter(f)
+		writer = f
 	} else {
-		writer = bufio.NewWriter(ctx.Stdout)
+		writer = ctx.Stdout
 	}
 
 	return c.dumpEntries(writer)
@@ -251,39 +252,39 @@ func (c *documentationCommand) readFileIds(path string) (map[string]string, erro
 	return ids, nil
 }
 
-func (c *documentationCommand) dumpEntries(writer *bufio.Writer) error {
+func (c *documentationCommand) dumpEntries(w io.Writer) error {
 	if len(c.super.subcmds) == 0 {
 		fmt.Printf("No commands found for %s", c.super.Name)
 		return nil
 	}
 
 	if !c.noIndex {
-		_, err := writer.WriteString(c.commandsIndex())
+		_, err := fmt.Fprintf(w, "%s", c.commandsIndex())
 		if err != nil {
 			return err
 		}
 	}
 
-	return c.writeSections(writer, []string{c.super.Name}, true)
+	return c.writeSections(w, []string{c.super.Name}, true)
 }
 
 // writeSections (recursively) writes sections for all commands to the given file.
-func (c *documentationCommand) writeSections(writer *bufio.Writer, superCommands []string, printDefaultCommands bool) error {
+func (c *documentationCommand) writeSections(w io.Writer, superCommands []string, printDefaultCommands bool) error {
 	sorted := c.getSortedListCommands()
 	for _, name := range sorted {
 		if !printDefaultCommands && isDefaultCommand(name) {
 			continue
 		}
 		ref := c.super.subcmds[name]
 		commandSeq := append(superCommands, name)
-		_, err := writer.WriteString(c.formatCommand(ref, true, commandSeq))
+		_, err := fmt.Fprintf(w, "%s", c.formatCommand(ref, true, commandSeq))
 		if err != nil {
 			return err
 		}
 
 		// Handle subcommands
 		if sc, ok := ref.command.(*SuperCommand); ok {
-			err = sc.documentation.writeSections(writer, commandSeq, false)
+			err = sc.documentation.writeSections(w, commandSeq, false)
 			if err != nil {
 				return err
 			}