fixed about.md typos, made hyperlinks for index.md in user guides, added...
fixed about.md typos, made hyperlinks for index.md in user guides, added monero tools, changed filenames of user guides.
knowledge-base/user-guides/Creating an Offline Backup of your Monero Account.md → knowledge-base/user-guides/Offline_Backup.md
knowledge-base/user-guides/Restoring your Monero Account.md → knowledge-base/user-guides/restore_account.md
knowledge-base/user-guides/how to create a view only wallet.md → knowledge-base/user-guides/view_only.md