update README, wiki, used libraries, screenshots, whats new dialog

[Robert Goldmann]

• README
• wiki
• used libraries (about page)
• screenshots
• what's new dialog

[Robert Goldmann]

✨ New features

✏️ Improvements

• updated dependencies #761

🐛 Bugfixes

• Fixed an error when uploading images when using MariaDB. #759

⚠️Deprecations

Minimum supported version of BudgetMaster database is now v2.10.0

❗ If you are still using BudgetMaster v2.9.2 or earlier, please make sure to upgrade to v2.10.0 prior to using this release! ❗

Minimum supported version for JSON import is now 4

❗ BudgetMaster database exports (JSON files) from version prior to v2.5.0 (version code 3 or less inside the JSON) can no longer be imported ❗