MM-55202-remove 'boards' from help command (#25225)

* remove 'boards' from help command

* remove boards from /help command

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/i18n/en.json

@@ -916,7 +916,7 @@
   },
   {
     "id": "api.command_help.success",
-    "translation": "Mattermost is an open source platform for secure communication, collaboration, and orchestration of work across tools and teams.\r\nMattermost contains three key tools:\r\n\r\n**Channels** - Stay connected with your team via 1:1 and group messaging.\r\n**[Playbooks](/playbooks)** - Build and configure repeatable processes to achieve specific and predictable outcomes.\r\n**[Boards](/boards)** - Manage projects and tasks in a Kanban board structure to help your team hit key milestones.\r\n\r\n[View documentation and guides]({{.HelpLink}})"
+    "translation": "Mattermost is an open source platform for secure communication, collaboration, and orchestration of work across tools and teams.\r\nMattermost contains two key tools:\r\n\r\n**Channels** - Stay connected with your team via 1:1 and group messaging.\r\n**[Playbooks](/playbooks)** - Build and configure repeatable processes to achieve specific and predictable outcomes.\r\n\r\n[View documentation and guides]({{.HelpLink}})"
   },
   {
     "id": "api.command_invite.channel.app_error",