feat: MessageEmbed#length (#3003)

* add MessageEmbed#length

* update typings (+MessageEmbed#length)

* eslint: L181 (max line length), L183 (missing semi)

* eslint: L181 (trailing space)

src/structures/MessageEmbed.js

@@ -169,6 +169,20 @@ class MessageEmbed {
     return this.color ? `#${this.color.toString(16).padStart(6, '0')}` : null;
   }
 
+  /**
+   * The accumulated length for the embed title, description, fields and footer text
+   * @type {number}
+   * @readonly
+   */
+  get length() {
+    return (
+      (this.title ? this.title.length : 0) +
+      (this.description ? this.description.length : 0) +
+      (this.fields.length >= 1 ? this.fields.reduce((prev, curr) =>
+        prev + curr.name.length + curr.value.length, 0) : 0) +
+      (this.footer ? this.footer.text.length : 0));
+  }
+
   /**
    * Adds a field to the embed (max 25).
    * @param {StringResolvable} name The name of the field