[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-power.h

@@ -1,3 +1,8 @@
+/**
+ * @file furi-hal-power.h
+ * Power HAL API
+ */
+
 #pragma once
 
 #include <stdint.h>
@@ -14,92 +19,142 @@ typedef enum {
     FuriHalPowerICFuelGauge,
 } FuriHalPowerIC;
 
-/** Initialize drivers */
+/** Initialize drivers
+ */
 void furi_hal_power_init();
 
-/**
- * Get current insomnia level
- * @return insomnia level: 0 - no insomnia, >0 - insomnia, bearer count.
+/** Get current insomnia level
+ *
+ * @return     insomnia level: 0 - no insomnia, >0 - insomnia, bearer count.
  */
 uint16_t furi_hal_power_insomnia_level();
 
-/**
- * Enter insomnia mode
- * Prevents device from going to sleep
- * @warning Internally increases insomnia level
- * Must be paired with furi_hal_power_insomnia_exit
+/** Enter insomnia mode Prevents device from going to sleep
+ * @warning    Internally increases insomnia level Must be paired with
+ *             furi_hal_power_insomnia_exit
  */
 void furi_hal_power_insomnia_enter();
 
-/**
- * Exit insomnia mode
- * Allow device to go to sleep
- * @warning Internally decreases insomnia level.
- * Must be paired with furi_hal_power_insomnia_enter
+/** Exit insomnia mode Allow device to go to sleep
+ * @warning    Internally decreases insomnia level. Must be paired with
+ *             furi_hal_power_insomnia_enter
  */
 void furi_hal_power_insomnia_exit();
 
-/** Check if sleep availble */
+/** Check if sleep availble
+ *
+ * @return     true if available
+ */
 bool furi_hal_power_sleep_available();
 
-/** Check if deep sleep availble */
+/** Check if deep sleep availble
+ *
+ * @return     true if available
+ */
 bool furi_hal_power_deep_sleep_available();
 
-/** Go to sleep */
+/** Go to sleep
+ */
 void furi_hal_power_sleep();
 
-/** Get predicted remaining battery capacity in percents */
+/** Get predicted remaining battery capacity in percents
+ *
+ * @return     remaining battery capacity in percents
+ */
 uint8_t furi_hal_power_get_pct();
 
-/** Get battery health state in percents */
+/** Get battery health state in percents
+ *
+ * @return     health in percents
+ */
 uint8_t furi_hal_power_get_bat_health_pct();
 
-/** Get charging status */
+/** Get charging status
+ *
+ * @return     true if charging
+ */
 bool furi_hal_power_is_charging();
 
-/** Poweroff device */
+/** Poweroff device
+ */
 void furi_hal_power_off();
 
-/** Reset device */
+/** Reset device
+ */
 void furi_hal_power_reset();
 
-/** OTG enable */
+/** OTG enable
+ */
 void furi_hal_power_enable_otg();
 
-/** OTG disable */
+/** OTG disable
+ */
 void furi_hal_power_disable_otg();
 
-/** Get OTG status */
+/** Get OTG status
+ *
+ * @return     true if enabled
+ */
 bool furi_hal_power_is_otg_enabled();
 
-/** Get remaining battery battery capacity in mAh */
+/** Get remaining battery battery capacity in mAh
+ *
+ * @return     capacity in mAh
+ */
 uint32_t furi_hal_power_get_battery_remaining_capacity();
 
-/** Get full charge battery capacity in mAh */
+/** Get full charge battery capacity in mAh
+ *
+ * @return     capacity in mAh
+ */
 uint32_t furi_hal_power_get_battery_full_capacity();
 
-/** Get battery voltage in V */
+/** Get battery voltage in V
+ *
+ * @param      ic    FuriHalPowerIc to get measurment
+ *
+ * @return     voltage in V
+ */
 float furi_hal_power_get_battery_voltage(FuriHalPowerIC ic);
 
-/** Get battery current in A */
+/** Get battery current in A
+ *
+ * @param      ic    FuriHalPowerIc to get measurment
+ *
+ * @return     current in A
+ */
 float furi_hal_power_get_battery_current(FuriHalPowerIC ic);
 
-/** Get temperature in C */
+/** Get temperature in C
+ *
+ * @param      ic    FuriHalPowerIc to get measurment
+ *
+ * @return     temperature in C
+ */
 float furi_hal_power_get_battery_temperature(FuriHalPowerIC ic);
 
-/** Get System voltage in V */
+/** Get System voltage in V
+ *
+ * @return     voltage in V
+ */
 float furi_hal_power_get_system_voltage();
 
-/** Get USB voltage in V */
+/** Get USB voltage in V
+ *
+ * @return     voltage in V
+ */
 float furi_hal_power_get_usb_voltage();
 
-/** Get power system component state */
+/** Get power system component state
+ */
 void furi_hal_power_dump_state();
 
-/** Enable 3.3v on external gpio and sd card */
+/** Enable 3.3v on external gpio and sd card
+ */
 void furi_hal_power_enable_external_3_3v();
 
-/** Disable 3.3v on external gpio and sd card */
+/** Disable 3.3v on external gpio and sd card
+ */
 void furi_hal_power_disable_external_3_3v();
 
 #ifdef __cplusplus