Windows javadoc encoding error fix (#246)

* windows javadoc encoding error fix

* windows-1252 standard double quotation

api/src/main/java/com/theokanning/openai/completion/chat/ChatMessage.java

@@ -1,14 +1,13 @@
 package com.theokanning.openai.completion.chat;
 
 import lombok.AllArgsConstructor;
-import lombok.Builder;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
 /**
- * <p>Each object has a role (either “system”, “user”, or “assistant”) and content (the content of the message). Conversations can be as short as 1 message or fill many pages.</p>
+ * <p>Each object has a role (either "system", "user", or "assistant") and content (the content of the message). Conversations can be as short as 1 message or fill many pages.</p>
  * <p>Typically, a conversation is formatted with a system message first, followed by alternating user and assistant messages.</p>
- * <p>The system message helps set the behavior of the assistant. In the example above, the assistant was instructed with “You are a helpful assistant.”<br>
+ * <p>The system message helps set the behavior of the assistant. In the example above, the assistant was instructed with "You are a helpful assistant."<br>
  * The user messages help instruct the assistant. They can be generated by the end users of an application, or set by a developer as an instruction.<br>
  * The assistant messages help store prior responses. They can also be written by a developer to help give examples of desired behavior.
  * </p>