docs(src): add examples alias and general cleanup (#2763)

src/main.h

@@ -1,11 +1,16 @@
 /**
  * @file src/main.h
- * @brief Main header file for the Sunshine application.
+ * @brief Declarations for the main entry point for Sunshine.
  */
-
-// macros
 #pragma once
 
-// functions
+/**
+ * @brief Main application entry point.
+ * @param argc The number of arguments.
+ * @param argv The arguments.
+ * @examples
+ * main(1, const char* args[] = {"sunshine", nullptr});
+ * @examples_end
+ */
 int
 main(int argc, char *argv[]);