Add command to generate Fission CLI docs (#2247)

* Add command to generate Fission CLI docs
* Minor fixes identified by LanguageTool

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

tools/cmd-docs/main.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/cobra/doc"
+
+	"github.com/fission/fission/cmd/fission-cli/app"
+)
+
+const fmTemplate = `---
+title: %s
+slug: %s
+url: %s
+---
+`
+
+const baseURL = "/docs/fission-cli/"
+
+var filePrepender = func(filename string) string {
+	name := filepath.Base(filename)
+	base := strings.TrimSuffix(name, path.Ext(name))
+	url := baseURL + strings.ToLower(base) + "/"
+	return fmt.Sprintf(fmTemplate, strings.Replace(base, "_", " ", -1), base, url)
+}
+
+var linkHandler = func(name string) string {
+	base := strings.TrimSuffix(name, path.Ext(name))
+	return baseURL + strings.ToLower(base) + "/"
+}
+
+func main() {
+	var outdir string
+	var rootCmd = &cobra.Command{
+		Use:   "fission-cli-docs",
+		Short: "Generate docs for fission-cli",
+		Long:  "Generate docs for fission-cli",
+		Run: func(cmd *cobra.Command, args []string) {
+			log.Printf("Generting docs in directory %s", outdir)
+			fissionApp := app.App()
+			fissionApp.DisableAutoGenTag = true
+			fissionApp.Short = "Serverless framework for Kubernetes"
+			err := doc.GenMarkdownTreeCustom(fissionApp, outdir, filePrepender, linkHandler)
+			if err != nil {
+				log.Fatal(err)
+			}
+		},
+	}
+	rootCmd.Flags().StringVarP(&outdir, "outdir", "o", "/tmp/cli-docs", "Output directory")
+
+	err := rootCmd.Execute()
+	if err != nil {
+		log.Fatal(err)
+	}
+}