Fixups for Homepage

- converted most content to plain Markdown
- minor re-writes to a couple sections (mainly "Be Part Of the Robot Evolution"
- inlined SVG triangles for black 'hero' section at top

Inlining the triangles avoids the 'pop-in' effect on page load, makes loads subjectively faster.

Though about inlining top parallax image, but 471kb is a bit large for that.