Feature: Multi-currency support (#5)

* change: new version config.yml

* refactor: yaml provider

* refactor: sqlite provider

* refactor: command supports multiple currencies.

* feat(config): upgrade config and data format to version 3

- Update config.yml to version 3
- Add support for multiple currencies
- Upgrade SQLite database to new format
- Update YAML data to new structure
- Add upgrade confirmation and migration process

* refactor: remove unused language files, update README.

README.md

@@ -20,14 +20,37 @@ Core of economy system for Nukkit
 
 ## For developers
 
+###  Single Currency Economies
+
 Developers can access to EconomyAPI's API by using:
 ```java
 EconomyAPI.getInstance().myMoney(player);
 EconomyAPI.getInstance().reduceMoney(player, amount);
 EconomyAPI.getInstance().addMoney(player, amount);
 ```
 
+> [!TIP]
+> Operating through the provider:
+> - `provider.addMoney(player, amount);`
+
+### Multiple Currency Economies
+
+**`currencyName`:** This parameter is a `String` that specifies the currency you want to interact with.  If your economy system supports multiple currencies (e.g., real-world currencies like "USD", "EUR", "GBP" or in-game items like "Gold", "Silver", "Diamonds"), you can use this parameter to target a specific currency.
+
+If your system only has one currency, use the first set of methods (without the `currencyName` parameter).
+
+```java
+EconomyAPI.getInstance().myMoney(player, currencyName);
+EconomyAPI.getInstance().reduceMoney(player, amount, currencyName);
+EconomyAPI.getInstance().addMoney(player, amount, currencyName);
+```
+
+> [!TIP]
+> When operating through the provider, the parameter order needs to be adjusted:
+> - `provider.addMoney(currencyName, player, amount);`
+
 ### Maven repository
+
 ```xml
 <repository>
     <id>nukkitx-repo</id>

pom.xml

@@ -2,10 +2,9 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
-    <groupId>me.onebone</groupId>
-    <artifactId>economyapi</artifactId>
-    <version>2.0.6-SNAPSHOT</version>
-    <name>EconomyAPI</name>
+    <groupId>me.onebone.economyapi.EconomyAPI</groupId>
+    <artifactId>EconomyAPI</artifactId>
+    <version>2.1.0-SNAPSHOT</version>
     <url>https://github.com/MemoriesOfTime/EconomyAPI</url>
 
     <repositories>
@@ -49,7 +48,26 @@
     </distributionManagement>
 
     <build>
-        <finalName>${project.name}-${project.version}</finalName>
+        <finalName>${project.name}-${project.version}-MOT</finalName>
+
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <includes>
+                    <include>**/plugin.yml</include>
+                </includes>
+                <filtering>true</filtering>
+            </resource>
+
+            <resource>
+                <directory>src/main/resources</directory>
+                <excludes>
+                    <exclude>**/plugin.yml</exclude>
+                </excludes>
+                <filtering>false</filtering>
+            </resource>
+        </resources>
+
         <defaultGoal>clean package</defaultGoal>
         <plugins>
             <plugin>