added Command annotations and OptionType enum

lib/src/main/java/net/tomatentum/marinara/command/annotation/RootCommand.java

@@ -0,0 +1,7 @@
+package net.tomatentum.marinara.command.annotation;
+
+public @interface RootCommand {
+    public String name();
+    public String description() default "";
+    public CommandOption[] options() default {};
+}

lib/src/main/java/net/tomatentum/marinara/command/annotation/SubCommand.java

@@ -0,0 +1,7 @@
+package net.tomatentum.marinara.command.annotation;
+
+public @interface SubCommand {
+    public String name();
+    public String description() default "";
+    public CommandOption[] options() default {};
+}

lib/src/main/java/net/tomatentum/marinara/command/annotation/SubCommandGroup.java

@@ -0,0 +1,6 @@
+package net.tomatentum.marinara.command.annotation;
+
+public @interface SubCommandGroup {
+    public String name();
+    public String description() default "";
+}

lib/src/main/java/net/tomatentum/marinara/command/option/OptionType.java

@@ -0,0 +1,16 @@
+package net.tomatentum.marinara.command.option;
+
+public enum OptionType {
+    ATTACHMENT,
+    BOOLEAN,
+    CHANNEL,
+    DECIMAL,
+    LONG,
+    MENTIONABLE,
+    ROLE,
+    STRING,
+    SUB_COMMAND,
+    SUB_COMMAND_GROUP,
+    UNKNOW,
+    USER
+}