[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/stdglue.h

@@ -1,3 +1,8 @@
+/**
+ * @file stdglue.h
+ * Furi: stdlibc glue
+ */
+
 #pragma once
 
 #include <stdbool.h>
@@ -7,31 +12,31 @@
 extern "C" {
 #endif
 
-/**
- * Write callback
- * @param _cookie - pointer to cookie (see stdio gnu extension)
- * @param data - pointer to data
- * @param size - data size
- * @warnign your handler must consume everything
+/** Write callback
+ * @param      _cookie  pointer to cookie (see stdio gnu extension)
+ * @param      data     pointer to data
+ * @param      size     data size @warnign your handler must consume everything
  */
 typedef void (*FuriStdglueWriteCallback)(void* _cookie, const char* data, size_t size);
 
 /** Initialized std library glue code */
 void furi_stdglue_init();
 
-/**
- * Set global STDOUT callback
- * @param callback - callback or NULL to clear
- * @return true on success, otherwise fail
- * @warning function is thread aware, use this API from the same thread
+/** Set global STDOUT callback
+ *
+ * @param      callback  callback or NULL to clear
+ *
+ * @return     true on success, otherwise fail
+ * @warning    function is thread aware, use this API from the same thread
  */
 bool furi_stdglue_set_global_stdout_callback(FuriStdglueWriteCallback callback);
 
-/**
- * Set STDOUT callback for your thread
- * @param callback - callback or NULL to clear
- * @return true on success, otherwise fail
- * @warning function is thread aware, use this API from the same thread
+/** Set STDOUT callback for your thread
+ *
+ * @param      callback  callback or NULL to clear
+ *
+ * @return     true on success, otherwise fail
+ * @warning    function is thread aware, use this API from the same thread
  */
 bool furi_stdglue_set_thread_stdout_callback(FuriStdglueWriteCallback callback);