Lower header level in MarkDown documents

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Guide: Add run-time actions

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
guide: Web Worker process initialization

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>