Set default brightness

[mgesteiro]

Updated begin() method to include a default non-zero brightness level.

Other changes:

• Updated example code to change pins in use as Arduino pins 0 and 1 should be avoided (they are the RX/TX pins)
• New basic connection schematic graphic (I hope you like it)
• Some small rewording here and there in the README
• Removed some trailing spaces and added \n at the end (recommended practice)
• Minor aesthetic changes in formatting
• Updated release to 1.8.1

As always, feel free to edit whatever you want. Best regards

[jasonacox]

This is fantastic! Brilliant work @mgesteiro ! And, I love the graphic and wordsmithing. Thank you! 🙏