Add "Explosion" Animation for Destroyed Words

[vivinarya]

Problem: Words disappear instantly when destroyed, which feels abrupt.

Task:

• When a word is destroyed, show a small explosion animation or brief graphic flash at the word’s location before it vanishes.
• Ideally, the explosion should not disrupt gameplay flow.

Acceptance Criteria:

• Animation plays at the point where each word is destroyed.
• Animation or effect is clearly visible but short.
• Implementation in script.js.