Update safety manual FAQ regarding the tests

Please consider updating the https://doc-snapshots.qt.io/qtsaferenderer/qtsr-faq.html

What kind of tests are included in the Qt Safe Renderer installation?

Check if some human understandable short answer can be delivered from the below text

QSR 1.2 version shall have more tests in addition to the unit tests. While unit tests have html documentation available, these additional tests do not have html documentation. (to be considered in the future)

But it could be worth of mentioning that we have test assets. These are meant for testing the QSR itself during its development, but users can adapt these to their own needs. 

• scripts for manual testing
  • capacity tests
  • startup time
  • test harness
• benchmark tests
  • Qt benchmark tests for the drawing algorithms (colour and global alpha) with different types of framebuffer image formats for compressed and uncompressed bitmaps.

see more information at need;

manual tests:

See: https://codereview.qt-project.org/gitweb?p=tqtc-boot2qt/qtsaferenderer.git;a=tree;f=tests/manual;h=85b4f74447e56be3ed62e4af59f2f882d5a27123;hb=refs/heads/1.2

benchmark:

https://codereview.qt-project.org/gitweb?p=tqtc-boot2qt/qtsaferenderer.git;a=tree;f=tests/auto/benchmark;h=5279973989eb42d80396a553c54509d2e5f7a552;hb=refs/heads/1.2