Fix indentation. Update doxygen comments

include/sta/signal.hpp

@@ -8,33 +8,35 @@
 
 namespace sta
 {
-	/**
-	 * @brief Interface for signal objects.
-	 */
-	class Signal
-	{
-	public:
-		/**
-		 * @brief Enter signaled state.
-		 */
-		virtual void notify() = 0;
-		/**
-		 * @brief Check signal state w/o changing it.
-		 *
-		 * @return True if in signaled state
-		 */
-		virtual bool peek() = 0;
-		/**
-		 * @brief Check signal state.
-		 *
-		 * @return True if in signaled state
-		 */
-		virtual bool test() = 0;
-		/**
-		 * @brief Wait until signaled state is entered.
-		 */
-		virtual void wait() = 0;
-	};
+    /**
+     * @brief Interface for signal objects.
+     *
+     * @ingroup sta_core
+     */
+    class Signal
+    {
+    public:
+        /**
+         * @brief Enter signaled state.
+         */
+        virtual void notify() = 0;
+        /**
+         * @brief Check signal state w/o changing it.
+         *
+         * @return True if in signaled state
+         */
+        virtual bool peek() = 0;
+        /**
+         * @brief Check signal state.
+         *
+         * @return True if in signaled state
+         */
+        virtual bool test() = 0;
+        /**
+         * @brief Wait until signaled state is entered.
+         */
+        virtual void wait() = 0;
+    };
 } // namespace sta