Implement blink rendering

Fixes #944

typings/xterm-headless.d.ts

@@ -55,6 +55,13 @@ declare module '@xterm/headless' {
      */
     cursorBlink?: boolean;
 
+    /**
+     * The interval in milliseconds for the blink attribute. This is the amount
+     * of time text remains visible or hidden before toggling. Set to 0 to
+     * disable blinking. The default is 0.
+     */
+    blinkIntervalDuration?: number;
+
     /**
      * The style of the cursor.
      */

typings/xterm.d.ts

@@ -64,6 +64,13 @@ declare module '@xterm/xterm' {
      */
     cursorBlink?: boolean;
 
+    /**
+     * The interval in milliseconds for the blink attribute. This is the amount
+     * of time text remains visible or hidden before toggling. Set to 0 to
+     * disable blinking. The default is 0.
+     */
+    blinkIntervalDuration?: number;
+
     /**
      * The style of the cursor when the terminal is focused.
      */