Add a single channel example

Added a single channel example with run limit and tilting
features. Refs #1104 and closes #1105.

examples/relay_chn_single/main/Kconfig.projbuild

@@ -0,0 +1,40 @@
+menu "Relay Channel Single Example Configuration"
+    
+    choice EXAMPLE_RLCHN_BTN_ACTIVE_LEVEL
+        prompt "Choose an active level for buttons"
+        default EXAMPLE_RLCHN_BTN_ACTIVE_LEVEL_LOW
+        help
+            Specify the active level for buttons.
+        
+        config EXAMPLE_RLCHN_BTN_ACTIVE_LEVEL_LOW
+            bool "Active level LOW"
+
+        config EXAMPLE_RLCHN_BTN_ACTIVE_LEVEL_HIGH
+            bool "Active level HIGH"
+    endchoice
+    
+    config EXAMPLE_RLCHN_BTN_UP_IO_NUM
+        int "GPIO number for UP button"
+        default 0
+    
+    config EXAMPLE_RLCHN_BTN_DOWN_IO_NUM
+        int "GPIO number for DOWN button"
+        default 1
+    
+    config EXAMPLE_RLCHN_BTN_STOP_IO_NUM
+        int "GPIO number for STOP button"
+        default 2
+    
+    config EXAMPLE_RLCHN_LED_INDICATOR_IO_NUM
+        int "GPIO number for LED indicator output"
+        default 3
+    
+    config EXAMPLE_RLCHN_BTN_LONG_PRESS_TIME_MS
+        int "Long press time in ms to start secondary actions"
+        range 1500 3000
+        default 2000
+        help
+            Long press time in milliseconds is required to start secondary actions 
+            like tilting and flipping.
+
+endmenu