feat: add renderPointsAsSquares and disableAlphaBlending

[flekschas]

Expose renderPointsAsSquares and disableAlphaBlending to allow finer control over performance increasing settings.

Description

What was changed in this pull request?

Added two props:

1. renderPointsAsSquares
2. disableAlphaBlending

Note that if performanceMode is true, both props are automatically true.

Why is it necessary?

Fixes #206

Examples

Normal

No Alpha Blending

Squared Points

Checklist

• Provided a concise title as a semantic commit message (e.g. "fix: correctly handle undefined properties")
• CHANGELOG.md updated
• Tests added or updated
• Documentation in README.md added or updated
• Example(s) added or updated
• Screenshot, gif, or video attached for visual changes

[TheStanian]

Sweet, looks good to me. Nice way of not breaking the existing API!