Fix wrong resistor band in simple audio player tutorial

[benrpinto]

What This PR Changes

• Corrected a diagram in the Simple Audio Player tutorial
• Changed bands on resistor from 10k ohms to 10 ohms to match specifications in the tutorial
• Changed image dimensions to match contribution guidelines

Contribution Guidelines

• [✓] I confirm that I have read the contribution guidelines and comply with them.

[benrpinto]

Judging by the simple-audio-player.md preview, it doesn't appear to cause any problems. The line (line 71) where the file is used doesn't do any fancy formatting that would need to be changed, it reads: ![LM386 mounting on breadboard](assets/LM386_AudioZero_bb.png)

Is there a way to properly preview the website? The Previewing Changes section at the bottom of the main readme mentions

The link to the preview will appear in the comments of the PR. This also works with Draft PRs, but not for PRs created from a fork.

But I created this PR from a fork, so there's no link here.