[FL-1906] Documentation: add Doxyfile, prepare sources for doxygen. (#741)

* Documentation: add Doxyfile, prepare sources for doxygen.

* Update ReadMe and remove obsolete CLA

* Add contribution guide

* Contributing: update text

* Correct spelling

core/furi/memmgr_heap.h

@@ -1,3 +1,8 @@
+/**
+ * @file memmgr_heap.h
+ * Furi: heap memory managment API and allocator
+ */
+
 #pragma once
 
 #include <stdint.h>
@@ -10,28 +15,32 @@ extern "C" {
 #define MEMMGR_HEAP_UNKNOWN 0xFFFFFFFF
 
 /** Memmgr heap enable thread allocation tracking
- * @param thread_id - thread id to track
+ *
+ * @param      thread_id  - thread id to track
  */
 void memmgr_heap_enable_thread_trace(osThreadId_t thread_id);
 
 /** Memmgr heap disable thread allocation tracking
- * @param thread_id - thread id to track
+ *
+ * @param      thread_id  - thread id to track
  */
 void memmgr_heap_disable_thread_trace(osThreadId_t thread_id);
 
 /** Memmgr heap get allocatred thread memory
- * @param thread_id - thread id to track
- * @return bytes allocated right now
+ *
+ * @param      thread_id  - thread id to track
+ *
+ * @return     bytes allocated right now
  */
 size_t memmgr_heap_get_thread_memory(osThreadId_t thread_id);
 
 /** Memmgr heap get the max contiguous block size on the heap
- * @return size_t max contiguous block size
+ *
+ * @return     size_t max contiguous block size
  */
 size_t memmgr_heap_get_max_free_block();
 
-/**
- * Print the address and size of all free blocks to stdout
+/** Print the address and size of all free blocks to stdout
  */
 void memmgr_heap_printf_free_blocks();