feat(cli): add manual command and restructure docs

Add `astro manual [protocol]` command that renders CLI reference docs
in the terminal using salt/printer markdown rendering. Docs are embedded
at compile time via go:embed.

Restructure docs/ into cli/, reference/, guides/, and pics/ for clear
separation of CLI manuals, Go API reference, educational content, and
conformance statements.

Author: ravisuhag

cli/manual.go

@@ -0,0 +1,91 @@
+package cli
+
+import (
+	"embed"
+	"fmt"
+	"strings"
+
+	"github.com/raystack/salt/cli/printer"
+	"github.com/spf13/cobra"
+)
+
+// protocols maps CLI protocol names to their doc filenames.
+var protocols = map[string]string{
+	"spp":  "spp.md",
+	"epp":  "epp.md",
+	"tm":   "tm.md",
+	"tc":   "tc.md",
+	"time": "time.md",
+	"cadu": "cadu.md",
+	"cltu": "cltu.md",
+}
+
+func manualCmd(docsFS embed.FS) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "manual [protocol]",
+		Short: "Display protocol reference manual",
+		Long:  "Display the CLI reference manual for a protocol. Run without arguments to list available topics.",
+		Annotations: map[string]string{
+			"group": "help",
+		},
+		ValidArgs: protocolNames(),
+		Args:      cobra.MaximumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if len(args) == 0 {
+				return printManualIndex()
+			}
+			return printManual(docsFS, args[0])
+		},
+	}
+
+	return cmd
+}
+
+func printManualIndex() error {
+	var sb strings.Builder
+	sb.WriteString("# Astro Manual\n\n")
+	sb.WriteString("Available protocol manuals:\n\n")
+	sb.WriteString("| Protocol | Command |\n")
+	sb.WriteString("|----------|---------|\n")
+	sb.WriteString("| Space Packet Protocol | `astro manual spp` |\n")
+	sb.WriteString("| Encapsulation Packet Protocol | `astro manual epp` |\n")
+	sb.WriteString("| TM Transfer Frames | `astro manual tm` |\n")
+	sb.WriteString("| TC Transfer Frames | `astro manual tc` |\n")
+	sb.WriteString("| Time Code Formats | `astro manual time` |\n")
+	sb.WriteString("| Channel Access Data Units | `astro manual cadu` |\n")
+	sb.WriteString("| Command Link Transmission Units | `astro manual cltu` |\n")
+
+	out, err := printer.Markdown(sb.String())
+	if err != nil {
+		return err
+	}
+	fmt.Print(out)
+	return nil
+}
+
+func printManual(docsFS embed.FS, protocol string) error {
+	filename, ok := protocols[protocol]
+	if !ok {
+		return fmt.Errorf("unknown protocol %q — run 'astro manual' to see available topics", protocol)
+	}
+
+	content, err := docsFS.ReadFile("docs/cli/" + filename)
+	if err != nil {
+		return fmt.Errorf("reading manual for %s: %w", protocol, err)
+	}
+
+	out, err := printer.Markdown(string(content))
+	if err != nil {
+		return err
+	}
+	fmt.Print(out)
+	return nil
+}
+
+func protocolNames() []string {
+	names := make([]string, 0, len(protocols))
+	for k := range protocols {
+		names = append(names, k)
+	}
+	return names
+}

cli/root.go

@@ -1,12 +1,14 @@
 package cli
 
 import (
+	"embed"
+
 	"github.com/raystack/salt/cli/commander"
 	"github.com/spf13/cobra"
 )
 
 // New creates the root command for the astro CLI.
-func New() *cobra.Command {
+func New(docsFS embed.FS) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "astro <command> <subcommand> [flags]",
 		Short: "CCSDS and ECSS space communication toolkit",
@@ -26,6 +28,7 @@ func New() *cobra.Command {
 	cmd.AddCommand(tcCmd())
 	cmd.AddCommand(caduCmd())
 	cmd.AddCommand(cltuCmd())
+	cmd.AddCommand(manualCmd(docsFS))
 
 	mgr := commander.New(cmd)
 	mgr.Init()