Added skill_require_db.txt documentation.

Signed-off-by: nanakiwurtz <nanakiwurtz240@gmail.com>

doc/skill_require_db.txt

@@ -0,0 +1,98 @@
+//===== rAthena Documentation ================================
+//= rAthena Skill Requirement Reference
+//===== By: ==================================================
+//= rAthena Dev Team
+//===== Last Updated: ========================================
+//= 20140719
+//===== Description: =========================================
+//= Explanation of the skill_require_db.txt file and structure.
+//============================================================
+
+Structure:
+SkillID,HPCost,MaxHPTrigger,SPCost,HPRateCost,SPRateCost,ZenyCost,RequiredWeapons,RequiredAmmoTypes,RequiredAmmoAmount,RequiredState,RequiredStatuses,SpiritSphereCost,RequiredItemID1,RequiredItemAmount1,RequiredItemID2,RequiredItemAmount2,RequiredItemID3,RequiredItemAmount3,RequiredItemID4,RequiredItemAmount4,RequiredItemID5,RequiredItemAmount5,RequiredItemID6,RequiredItemAmount6,RequiredItemID7,RequiredItemAmount7,RequiredItemID8,RequiredItemAmount8,RequiredItemID9,RequiredItemAmount9,RequiredItemID10,RequiredItemAmount10,RequiredEquipment
+
+---------------------------------------
+
+SkillID: The ID of the skill. (See \db\[re|pre-re]\skill_db.txt for more details)
+
+---------------------------------------
+
+HPCost:	Amount of HP needed to use the skill.
+
+---------------------------------------
+
+MaxHPTrigger: Player's HP has to be below this % of Max HP, in order to use the skill.
+
+---------------------------------------
+
+SPCost: Amount of SP needed to use the skill.
+
+---------------------------------------
+
+HPRateCost: If more than 0, it's a percentage of the player's current HP. If less than 0, it's a percentage of the player's Max HP.
+
+---------------------------------------
+
+SPRateCost: If more than 0, it's a percentage of the player's current SP. If less than 0, it's a percentage of the player's Max SP.
+
+---------------------------------------
+
+ZenyCost: Amount of Zeny needed to use the skill.
+
+---------------------------------------
+
+RequiredWeapons: Player needs to equip this weapon to use the skill. (Use Item ID).
+
+---------------------------------------
+
+RequiredAmmoTypes: Player needs to equip this ammo to use the skill. (Use Item ID).
+
+---------------------------------------
+
+RequiredAmmoAmount: Amount of ammo needed to use the skill.
+
+---------------------------------------
+
+RequiredState: Specify the 'State' required to be active, in order to use the skill.
+none = Nothing special.
+hidden = Requires hidden status by using Hiding, Cloaking, or Chasewalk.
+riding = Requires the player to ride either a Peco or a Dragon.
+falcon = Requires a Falcon.
+cart = Requires a Pushcart (For renewal, this state can be replaced by SC_PUSH_CART in 'RequiredStatuses' field).
+shield = Requires a shield equipped.
+recover_weight_rate = Requires to be less than 50% weight.
+move_enable = Requires to be able to move.
+water = Requires to be standing on a water cell.
+dragon = Requires to ride a Dragon.
+warg = Requires a Warg.
+ridingwarg = Requires to ride a Warg.
+mado = Requires to have an active Mado.
+elementalspirit = Requires to have an Elemental Spirit summoned.
+peco = Requires riding a Peco.
+
+---------------------------------------
+
+RequiredStatuses: List of status needed to be active, in order to use the skill.
+Example usage of values = SC_STATUS1:SC_STATUS2:SC_STATUS3 (see db/const.txt for more details).
+Maximum multiple value is 3. (Refer to skill.h: MAX_SKILL_STATUS_REQUIRE)
+Use any number or SC_ALL to disable status requirements.
+
+---------------------------------------
+
+SpiritSphereCost: Amount of Spirit Sphere needed to use the skill.
+
+---------------------------------------
+
+RequiredItemID1-10: These items will be used when players use the skill. Maximum of 10 items.
+
+---------------------------------------
+
+RequiredItemAmount1-10: Amount of item used when player uses the skill.
+
+---------------------------------------
+
+RequiredEquipment: Player needs to equip these equipments to use the skill. (Use Item ID).
+Example usage of multiple values = item1:item2:item3
+Maximum multiple value is 10. (Refer to skill.h: MAX_SKILL_EQUIP_REQUIRE)
+
+---------------------------------------