[Feature Request]: Global Snippets to reduce maintenance work across docs

### Prerequisites

- [x] I have searched existing issues to ensure this feature hasn't already been requested
- [x] I have tested using the latest version of docs-builder

### What problem are you trying to solve?

Whenever a reorg happens and/or ownership of products change within a company, we have to go through all our docs/repositories to update department entries and/or standardized messaging, for example the quote below.

> Reach out to [Team X](Link to our support channel) in case you need more help.

One could use redirects to have a long-standing link, but the "Team X" text would still require changes across all repositories owned by the team, and with that, all the approval and release process.

### Proposed Solution

Have a space (somewhere) I can link to outside the current product's documentation.

### Examples and Research

Notion has [Synced blocks](https://www.notion.com/help/synced-blocks) for this purpose.

### Alternative Solutions

_No response_

### Additional Context

I have been discussing this feature with @theletterf, @reakaleek, and @Mpdreamz internally ([thread](https://elastic.slack.com/archives/C07APH4RCDT/p1774279104789529)).

### How important is this feature to you?

Nice to have