feat: add help-all command (#1768)

Author: suzuki-shunsuke

Diff for: go.mod

@@ -16,6 +16,7 @@ require (
 	github.com/suzuki-shunsuke/github-comment-metadata v0.1.0
 	github.com/suzuki-shunsuke/go-ci-env/v3 v3.1.0
 	github.com/suzuki-shunsuke/go-error-with-exit-code v1.0.0
+	github.com/suzuki-shunsuke/urfave-cli-help-all v0.0.2
 	github.com/urfave/cli/v2 v2.27.5
 	golang.org/x/oauth2 v0.25.0
 	golang.org/x/term v0.28.0

Diff for: go.sum

@@ -77,6 +77,8 @@ github.com/suzuki-shunsuke/go-ci-env/v3 v3.1.0 h1:WHVT7TZTVITrKiIvW7i5+4vr8ebxD6
 github.com/suzuki-shunsuke/go-ci-env/v3 v3.1.0/go.mod h1:qnHYP5fJLLNKqOwxCfix7XVzQGfbF72vbGgLhl8X2vA=
 github.com/suzuki-shunsuke/go-error-with-exit-code v1.0.0 h1:oVXrrYNGBq4POyITQNWKzwsYz7B2nUcqtDbeX4BfeEc=
 github.com/suzuki-shunsuke/go-error-with-exit-code v1.0.0/go.mod h1:kDFtLeftDiIUUHXGI3xq5eJ+uAOi50FPrxPENTHktJ0=
+github.com/suzuki-shunsuke/urfave-cli-help-all v0.0.2 h1:5MQhRCdZz4AbXxZOXjmMFK4PurBJ+h7emFrau9TZaRY=
+github.com/suzuki-shunsuke/urfave-cli-help-all v0.0.2/go.mod h1:sSi6xaUaHfaqu32ECLeyE7NTMv+ZM5dW0JikhllaalY=
 github.com/urfave/cli/v2 v2.27.5 h1:WoHEJLdsXr6dDWoJgMq/CboDmyY/8HMMH1fTECbih+w=
 github.com/urfave/cli/v2 v2.27.5/go.mod h1:3Sevf16NykTbInEnD0yKkjDAeZDS0A6bzhBH5hrMvTQ=
 github.com/wk8/go-ordered-map/v2 v2.1.8 h1:5h/BUHu93oj4gIdvHHHGsScSTMijfx5PeYkE/fJgbpc=

Diff for: pkg/cmd/app.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"io"
 
+	"github.com/suzuki-shunsuke/urfave-cli-help-all/helpall"
 	"github.com/urfave/cli/v2"
 )
 
@@ -257,6 +258,7 @@ func (r *Runner) Run(ctx context.Context, args []string) error { //nolint:funlen
 					},
 				},
 			},
+			helpall.New(nil),
 		},
 		Flags: []cli.Flag{
 			&cli.StringFlag{