main_window: when no devices found on linux, link to udev guide

src/main/python/main_window.py

@@ -6,6 +6,7 @@ from PyQt5.QtWidgets import QWidget, QComboBox, QToolButton, QHBoxLayout, QVBoxL
 
 import json
 import os
+import sys
 from urllib.request import urlopen
 
 from editor_container import EditorContainer
@@ -69,10 +70,14 @@ class MainWindow(QMainWindow):
         self.tabs.currentChanged.connect(self.on_tab_changed)
         self.refresh_tabs()
 
-        self.lbl_no_devices = QLabel(tr("MainWindow", 'No devices detected. Connect a Vial-compatible device and press '
-                                                      '"Refresh"\n'
-                                                      'or select "File" → "Download VIA definitions" in order to enable'
-                                                      ' support for VIA keyboards.'))
+        no_devices = 'No devices detected. Connect a Vial-compatible device and press "Refresh"<br>' \
+                     'or select "File" → "Download VIA definitions" in order to enable support for VIA keyboards.'
+        if sys.platform.startswith("linux"):
+            no_devices += '<br><br>On Linux you need to set up a custom udev rule for keyboards to be detected. ' \
+                          'Follow the instructions linked below:<br>' \
+                          '<a href="https://get.vial.today/getting-started/linux-udev.html">https://get.vial.today/getting-started/linux-udev.html</a>'
+        self.lbl_no_devices = QLabel(tr("MainWindow", no_devices))
+        self.lbl_no_devices.setTextFormat(Qt.RichText)
         self.lbl_no_devices.setAlignment(Qt.AlignCenter)
 
         layout = QVBoxLayout()