Replaced Win32 source build instructions with binary download instructions.
Updated from commit e227a07c8fb05200275bdfdce1b8cdecfcde3105.
Updated URL.
Updated from commit 2cc4ff465f5479e8893fab46ea77bc2334c846e1.
Updated from commit a0216473d51df38e8df31be13d7d7a131d98fe2d.
Updated from commit c0b5be99445a50f83f2282ef2dbd3fe08912eb30.
Updated from commit 4ea84c484331d9f14b4a0c475f2a64dd654f8fed.
Updated from commit 1d6000213caac2286367392e45af3229b4378e79.
Retrofit simplifications from doc.css.
LOADER.SYSTEM is part of cc65 for some time by now.