Improve Clarity of Syncthing Configuration documentation: rename 'Synopsis' section and add overview.

[chaosORCHESTRA]

Description

The current "Synopsis" section in the Syncthing Configuration documentation is confusing for new users. It displays file paths instead of providing an actual synopsis/summary of the page content.

Current behavior

Under the "Synopsis" heading, the documentation shows:
$XDG_STATE_HOME/syncthing
$HOME/.local/state/syncthing
$HOME/Library/Application Support/Syncthing %LOCALAPPDATA%\Syncthing

Expected behavior

1. These file paths should be under a more descriptive heading like "Configuration File Locations" or "Default Configuration Paths"
2. An actual synopsis/overview section should be added at the beginning to help users understand what the configuration page covers

Suggested improvements

1. Rename "Synopsis" to "Configuration File Locations"
2. Add a new "Overview" or "Introduction" section with a brief summary, for example:

   "This page covers how to configure Syncthing for file synchronization, including device setup, folder configuration, connection settings, and various configuration methods through the web GUI, command-line, or direct file editing."

Additional context

As a new user, I found this confusing because "synopsis" typically means a brief summary, not a list of file paths.