Created CONTRIBUTING.md and updated checkstyle.xml

CONTRIBUTING.md

@@ -0,0 +1,31 @@
+# How to contribute to EcoEnchants
+
+## Codestyle
+1. The EcoEnchants checkstyle is in /config/checkstyle.xml
+- The pull request must not have any checkstyle issues.
+- Every method and field must have a javadoc attached.
+
+2. Use sonarlint (base config) if possible.
+
+3. Use lombok wherever possible.
+- As of 6.0.0, EcoEnchants is now built with lombok.
+- @Getter, @Setter, @ToString, @EqualsAndHashCode, @UtilityClass are the most important.
+
+4. Use JetBrains annotations
+- Every parameter should be annotated with @NotNull or @Nullable
+- Use @NotNull over lombok @NonNull
+
+5. Imports
+- No group (*) imports.
+- No static imports.
+
+## Dependency Injection
+- EcoEnchants uses Dependency Injection since 6.0.0.
+- Any calls to AbstractEcoPlugin#getInstance are code smells and should never be used unless **absolutely necessary**.
+- NamespacedKeys, FixedMetadataValues, Runnables, and Schedules should be managed using EcoEnchantsPlugin through DI.
+- Any DI class should extend PluginDependent where possible. If the class extends another, then you **must** store the plugin instance in a private final variable called **plugin** with a private or protected getter.
+
+## Other
+- All drops **must** be sent through a DropQueue - calls to World#dropItem will get your PR rejected.
+- EcoEnchants is built with java 8. Usage of J9+ will get your PR rejected.
+- Any non-plugin-specific changes **must** be made to eco-util, or core-proxy, rather than core-plugin.

config/checkstyle/checkstyle.xml

@@ -87,16 +87,14 @@
 
     <module name="TreeWalker">
 
-        <!--
-        Checks for Javadoc comments.
-        See https://checkstyle.org/config_javadoc.html
+        <!-- Checks for Javadoc comments. -->
+        <!-- See https://checkstyle.org/config_javadoc.html -->
         <module name="InvalidJavadocPosition"/>
         <module name="JavadocMethod"/>
         <module name="JavadocType"/>
         <module name="JavadocVariable"/>
         <module name="JavadocStyle"/>
         <module name="MissingJavadocMethod"/>
-        -->
 
         <!-- Checks for Naming Conventions.                  -->
         <!-- See https://checkstyle.org/config_naming.html -->