Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/channels/app/slashcommands/command_shortcuts.go

@@ -0,0 +1,44 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package slashcommands
+
+import (
+	"github.com/mattermost/mattermost-server/v6/model"
+	"github.com/mattermost/mattermost-server/v6/server/channels/app"
+	"github.com/mattermost/mattermost-server/v6/server/channels/app/request"
+	"github.com/mattermost/mattermost-server/v6/server/platform/shared/i18n"
+)
+
+type ShortcutsProvider struct {
+}
+
+const (
+	CmdShortcuts = "shortcuts"
+)
+
+func init() {
+	app.RegisterCommandProvider(&ShortcutsProvider{})
+}
+
+func (*ShortcutsProvider) GetTrigger() string {
+	return CmdShortcuts
+}
+
+func (*ShortcutsProvider) GetCommand(a *app.App, T i18n.TranslateFunc) *model.Command {
+	return &model.Command{
+		Trigger:          CmdShortcuts,
+		AutoComplete:     true,
+		AutoCompleteDesc: T("api.command_shortcuts.desc"),
+		AutoCompleteHint: "",
+		DisplayName:      T("api.command_shortcuts.name"),
+	}
+}
+
+func (*ShortcutsProvider) DoCommand(a *app.App, c request.CTX, args *model.CommandArgs, message string) *model.CommandResponse {
+	// This command is handled client-side and shouldn't hit the server.
+	return &model.CommandResponse{
+		Text:         args.T("api.command_shortcuts.unsupported.app_error"),
+		ResponseType: model.CommandResponseTypeEphemeral,
+	}
+}