Add user-guide for Windows binary verification, add entry to index.md, and add images to png/ dir.

Fix some jekyll serve errors pertaining to the Qubes/Whonix isolation guide:
+ In resources/user-guides/cli_wallet_daemon_isolation_qubes_whonix.md change from `static_page` to `user-guide`. Fixes error: `Missing i18n key: en:CLI Wallet/Daemon Isolation with Qubes + Whonix`.
+ Qubes/Whonix guide was missing from Italian lang section, prevented serving site. Apparently this also alphabetized the Italian lang sections index when I copied an index.md from another lang there.