Update docs from txt to Markdown (rathena#7975)

* Update and rename packet_struct_notation.txt to packet_struct_notation.md
* Update and rename achievements.txt to achievements.md
* Update and rename effect_list.txt to effect_list.md

---------

Co-authored-by: Lemongrass3110 <[email protected]>
Co-authored-by: Atemo <[email protected]>
Co-authored-by: Aleos <[email protected]>

doc/achievements.md

@@ -0,0 +1,165 @@
+# Achievement Database Structure
+
+# Table of contents
+1. [Id](#id)
+2. [Group](#group)
+    1. [Valid Groups](#valid-groups)
+4. [Name](#name)
+5. [Targets](#targets)
+6. [Condition](#condition)
+7. [Map](#map)
+8. [Dependents](#dependents)
+9. [Rewards](#rewards)
+10. [Score](#score)
+11. [Example](#example)
+
+### Id <a name="id"></a>
+
+Unique achievement ID.
+
+### Group <a name="group"></a>
+
+Achievement group type.
+Each achievement type calls a specific objective check.
+
+#### Valid groups <a name="valid-groups"></a>
+
+<ul>
+  <li><code>None</code> - Can be used for custom achievements that are given through a script with no trigger events.</li>
+  <li><code>Add_Friend</code> - Triggered when a player adds a friend.</li>
+  <li><code>Adventure</code> - Does not trigger automatically. These are triggered by the achievementcomplete script command.</li>
+  <li><code>Baby</code> - Triggered when a player becomes a baby job.</li>
+  <li><code>Battle</code> - Triggered when a player kills a monster.</li>
+  <li><code>Chatting</code> - Aegis uses this when talking to a NPC. These are triggered by the achievementupdate script command.</li>
+  <li><code>Chatting_Count</code> - Triggered when a player has a chatroom open and others join.</li>
+  <li><code>Chatting_Create</code> - Triggered when a player creates a chatroom.</li>
+  <li><code>Chatting_Dying</code> - Triggered when a player creates a chatroom and dies with it open.</li>
+  <li><code>Eat</code> - Unknown.</li>
+  <li><code>Get_Item</code> - Triggered when a player gets an item that has a specific sell value.</li>
+  <li><code>Get_Zeny</code> - Triggered when a player gets a specific amount of zeny at once.</li>
+  <li><code>Goal_Achieve</code> - Triggered when a player's achievement rank levels up.</li>
+  <li><code>Goal_Level</code> - Triggered when a player's base level or job level changes.</li>
+  <li><code>Goal_Status</code> - Triggered when a player's base stats changes.</li>
+  <li><code>Job_Change</code> - Triggered when a player's job changes.</li>
+  <li><code>Marry</code> - Triggered when two players get married.</li>
+  <li><code>Party</code> - Triggered when a player creates a party.</li>
+  <li><code>Enchant_Fail</code> - Triggered when a player fails to refine an equipment.</li>
+  <li><code>Enchant_Success</code> - Triggered when a player successfully refines an equipment.</li>
+  <li><code>Spend_Zeny</code> - Triggered when a player spends any amount of zeny on vendors.</li>
+  <li><code>Taming</code> - Triggered when a player tames a monster.</li>
+</ul>
+
+### Name <a name="name"></a>
+
+Achievement name. Used when sending rewards through RODEX.
+
+### Targets <a name="targets"></a>
+
+A list of monster names and count values that the achievement requires. The target count can also be used for
+achievements that keep a counter while not being related to monster kills. Capped at `MAX_ACHIEVEMENT_OBJECTIVES`. See
+examples below:
+
+Player must kill 5 Scorpions and 10 Porings
+
+```yml
+  Targets:
+    - Id: 0
+      Mob: SCORPION
+      Count: 5
+    - Id: 1
+      Mob: PORING
+      Count: 10
+```
+
+Player must have 100 or more of ARG0 value. Using the count target value is useful for achievements that are increased
+in increments and not checked for a total (UI_Type = 1). IE: In the achievement_list.lub file, UI_Type 0 is displayed as
+non-incremental while 1 shows a progress bar of completion for the achievement.
+
+```yml
+Condition: " ARG0 >= 100 "
+  Targets:
+    - Id: 0 // Array index value
+      Count: 100
+```
+
+### Condition <a name="condition"></a>
+
+A conditional statement that must be met for the achievement to be considered complete. Accepts script constants, player
+variables, and ARGX (where X is the argument vector value). The ARGX values are sent from the server to the achievement
+script engine on special events. See examples below:
+
+This function will send 1 argument (ARG0) with a value of i + 1 when a friend is added.
+
+```yml
+achievement_update_objective(f_sd, AG_ADD_FRIEND, 1, i + 1);
+```
+
+This function will send 2 arguments (ARG0 and ARG1) with values of weapon level and refine level, respectively, when an
+equipment is successfully refined.
+
+```yml
+achievement_update_objective(sd, AG_REFINE_SUCCESS, 2, sd->inventory_data[i]->wlv, sd->inventory.u.items_inventory[i].refine);
+```
+
+### Map <a name="map"></a>
+
+A map name that is used for the Chatting group which increments the counter based on the player's map.
+> NOTICE: This option is currently disabled until the official behavior is confirmed.
+
+### Dependents <a name="dependents"></a>
+
+A list of achievement IDs that need to be completed before this achievement is considered complete. See examples below:
+
+Player must complete achievements 10001 and 10002 first.
+
+```yml
+Dependents:
+  10001: true
+  10002: true
+```
+
+Used with the import, dependent achievements can be disabled. The player now only requires completion of achievement
+10001.
+
+```
+Dependents:
+  10002: false
+```
+
+### Rewards <a name="rewards"></a>
+
+A list of rewards that are given on completion. All fields are optional.
+
+```yml
+Item: Item Name
+Amount:
+  Amount of Item (Default: 1)
+Script: Bonus Script
+TitleId: Title ID
+```
+
+### Score <a name="score"></a>
+
+Achievement points that are given on completion.
+
+### Example <a name="example"></a>
+
+```yml
+ - Id: 99
+   Group: Baby
+   Name: Example Achieve
+   Targets:
+     - Id: 0
+       Mob: XM_CELINE_KIMI
+       Count: 1
+   Condition: " BaseLevel >= 99 "
+   Map: prontera
+   Dependents:
+     - Id: 100
+   Rewards:
+     Item: Shabby_Purse
+     Amount: 10
+     Script: " specialeffect2 EF_BLESSING; sc_start SC_BLESSING,30000,10; "
+     TitleId: 1000
+   Score: 10
+```