Public 2.0: UI - Optimize toolkit screenshots

[hetmanchuk]

Describe the bug There are 3 very large, not optimized screenshots (2700+ pix width) in the page https://supergiant.io/toolkit/

To Reproduce Steps to reproduce the behavior:

1. Go to https://supergiant.io/toolkit/
2. Open 2 screenshots

• https://supergiant.io/wp-content/uploads/2018/11/cluster-usage-stats.png
• https://supergiant.io/wp-content/uploads/2018/11/sg-capacity-2-2x.png
• https://supergiant.io/wp-content/uploads/2018/11/analyze-2.png

Expected behavior All 3 images looking good on HD/retina and at the same time are optimized.

[hetmanchuk]

This is DONE. @gopherstein