[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-sd.h

@@ -1,3 +1,8 @@
+/**
+ * @file furi-hal-sd.h
+ * SD Card HAL API
+ */
+
 #include <stdint.h>
 #include <stdbool.h>
 
@@ -5,19 +10,20 @@
 extern "C" {
 #endif
 
-/** Init SD card detect */
+/** Init SD card detect
+ */
 void hal_sd_detect_init(void);
 
-/** Set SD card detect pin to low */
+/** Set SD card detect pin to low
+ */
 void hal_sd_detect_set_low(void);
 
-/**
- * Get SD card status
- * @return true if SD card present
- * @return false if SD card not present
+/** Get SD card status
+ *
+ * @return     true if SD card present, false if SD card not present
  */
 bool hal_sd_detect(void);
 
 #ifdef __cplusplus
 }
-#endif
+#endif