[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

firmware/targets/furi-hal-include/furi-hal-vcp.h

@@ -1,3 +1,8 @@
+/**
+ * @file furi-hal-vcp.h
+ * VCP HAL API
+ */
+
 #pragma once
 
 #include <stdbool.h>
@@ -8,35 +13,34 @@
 extern "C" {
 #endif
 
-/**
- * Init VCP HAL
- * Allocates ring buffer and initializes state
+/** Init VCP HAL Allocates ring buffer and initializes state
  */
 void furi_hal_vcp_init();
 
-/**
- * Recieve data from VCP
- * Waits till some data arrives, never returns 0
- * @param buffer - pointer to buffer
- * @param size - buffer size
- * @return items copied in buffer, 0 if channel closed
+/** Recieve data from VCP Waits till some data arrives, never returns 0
+ *
+ * @param      buffer  pointer to buffer
+ * @param      size    buffer size
+ *
+ * @return     items copied in buffer, 0 if channel closed
  */
 size_t furi_hal_vcp_rx(uint8_t* buffer, size_t size);
 
-/**
- * Recieve data from VCP with timeout
- * Waits till some data arrives during timeout
- * @param buffer - pointer to buffer
- * @param size - buffer size
- * @param timeout - rx timeout in ms
- * @return items copied in buffer, 0 if channel closed or timeout occurs
+/** Recieve data from VCP with timeout Waits till some data arrives during
+ * timeout
+ *
+ * @param      buffer   pointer to buffer
+ * @param      size     buffer size
+ * @param      timeout  rx timeout in ms
+ *
+ * @return     items copied in buffer, 0 if channel closed or timeout occurs
  */
 size_t furi_hal_vcp_rx_with_timeout(uint8_t* buffer, size_t size, uint32_t timeout);
 
-/**
- * Transmit data to VCP
- * @param buffer - pointer to buffer
- * @param size - buffer size
+/** Transmit data to VCP
+ *
+ * @param      buffer  pointer to buffer
+ * @param      size    buffer size
  */
 void furi_hal_vcp_tx(const uint8_t* buffer, size_t size);