Screenshot changes and other minor improvements

• Update manual and guided tour

• Organize screenshots into three sections: bundled applications, publicly available applications, user screenshots of potentially not publicly available applications.

• Add screenshots

  • Inspector (bundled)

  • Debugger (bundled, copied from it7-cap-2017-debugger.png)

  • Flamegraph Viewer (publicly available)

• Add quote by Nikodemus Siivola to excite page.