What's new and user guide: refinements for 2019.3 (#10497)
* User guide: refine sections 13.1 and 13.5. Re #10495.
Section 13.1: mention that OneCore is used in Windows 10 by default.
Section 13.5: mention that Espeak NG is used in other Windows releases other than 10. For both sections, anchors for synth sections were added.
* User guide: remove Audiologic section (section 13.6). Re #10496.
As Audiologic synth driver module is gone in NVDA 2019.3, Audiologic section should be removed from the user guide. Thus section 13.6 is deleted.
* What's new: Windows 10 version names, clarity, grammar.
Windows 10 versions are once again denoted with public names instead of version YYMM.
Various clarifications and grammar fixes, specifically punctuation.
