refactor: migrate from submodules to multi-root workspace for plugins (#198)

* refactor: migrate from submodules to multi-root workspace for plugins

- Updated LEDMatrix.code-workspace to include all plugin repos as root folders
- Removed symlinks from plugin-repos/ and plugins/ directories
- Updated .gitignore to reflect new plugin management approach
- Added setup_plugin_repos.py script for managing plugin symlinks (if needed)
- Added MULTI_ROOT_WORKSPACE_SETUP.md documentation

Plugins are now managed as independent repositories via multi-root workspace,
allowing for easier development and independent updates without modifying
the LEDMatrix project structure.

* Fix MULTI_ROOT_WORKSPACE_SETUP.md and add JSON error handling

- Remove deprecated clone_plugin_repos.py command reference
- Add language tag to directory tree code fence (fixes MD040)
- Add JSONDecodeError handling in setup_plugin_repos.py with user-friendly error messages

---------

Co-authored-by: Chuck <chuck@example.com>

LEDMatrix.code-workspace

@@ -1,7 +1,99 @@
 {
-    "folders": [
-        {
-            "path": "."
-        }
-    ]
-}
+	"folders": [
+		{
+			"path": ".",
+			"name": "LEDMatrix (Main)"
+		},
+		{
+			"path": "../ledmatrix-odds-ticker",
+			"name": "Odds Ticker"
+		},
+		{
+			"path": "../ledmatrix-clock-simple",
+			"name": "Clock Simple"
+		},
+		{
+			"path": "../ledmatrix-text-display",
+			"name": "Text Display"
+		},
+		{
+			"path": "../ledmatrix-basketball-scoreboard",
+			"name": "Basketball Scoreboard"
+		},
+		{
+			"path": "../ledmatrix-soccer-scoreboard",
+			"name": "Soccer Scoreboard"
+		},
+		{
+			"path": "../ledmatrix-calendar",
+			"name": "Calendar"
+		},
+		{
+			"path": "../ledmatrix-olympics-countdown",
+			"name": "Olympics Countdown"
+		},
+		{
+			"path": "../ledmatrix-stocks",
+			"name": "Stocks"
+		},
+		{
+			"path": "../ledmatrix-music",
+			"name": "Music"
+		},
+		{
+			"path": "../ledmatrix-static-image",
+			"name": "Static Image"
+		},
+		{
+			"path": "../ledmatrix-football-scoreboard",
+			"name": "Football Scoreboard"
+		},
+		{
+			"path": "../ledmatrix-hockey-scoreboard",
+			"name": "Hockey Scoreboard"
+		},
+		{
+			"path": "../ledmatrix-baseball-scoreboard",
+			"name": "Baseball Scoreboard"
+		},
+		{
+			"path": "../ledmatrix-christmas-countdown",
+			"name": "Christmas Countdown"
+		},
+		{
+			"path": "../ledmatrix-flights",
+			"name": "Flights"
+		},
+		{
+			"path": "../ledmatrix-leaderboard",
+			"name": "Leaderboard"
+		},
+		{
+			"path": "../ledmatrix-weather",
+			"name": "Weather"
+		},
+		{
+			"path": "../ledmatrix-news",
+			"name": "News"
+		},
+		{
+			"path": "../ledmatrix-of-the-day",
+			"name": "Of The Day"
+		},
+		{
+			"path": "../ledmatrix-youtube-stats",
+			"name": "YouTube Stats"
+		},
+		{
+			"path": "../ledmatrix-plugins",
+			"name": "Plugin Registry"
+		}
+	],
+	"settings": {
+		"files.exclude": {
+			"**/.git": true,
+			"**/__pycache__": true,
+			"**/*.pyc": true
+		}
+	}
+}