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.
I believe I made this guide correctly. This merge request contain the following changes:
1. A new GUI solo mining user guide
2. A link to the guide on the user guides page
3. Several images in the PNG folder that are referenced
4. An update to the prove payment user guide to include information about how to get the transaction key in the GUI
This is my first time using Git desktop, so apologies if I screwed this all up.
