[master < T1178] Update the description of SHOW INDEX INFO output

[antepusic]

Description

Per memgraph#1178, the output of SHOW INDEX INFO is sorted. This PR adds that info to the docs.

Pull request type

• [x] Documentation improvements

Related PRs and issues

memgraph#1178

Checklist:

• [x] I checked all content with Grammarly
• [x] I performed a self-review of my code
• [x] I made corresponding changes to the rest of the documentation
• [x] The build passes locally
• [x] My changes generate no new warnings or errors

[antepusic]

Superseded by the change of repository to /documentation.