Update fts example according to a new set of roles

[lovtsovaik]

Environment

• Documentation version: 7.2
• Part of the documentation: FTS
• Existing page: https://doc.cuba-platform.com/fts-7.2/fts.html#qs_project_setup

Description of the bug or enhancement

See the last sentence in paragraph 3.1 and Figure 4. Search Results.
Administrators role does not exist, so searching the "adm" string gives only one user as a result.
The current list of roles:

It is necessary to update the picture and search example (e.g. "mini").

Upd. Design-time roles are not indexed, and search by design-time roles will give no result, see #760

Also, screenshots can be changed in #759