Add release summary for 2020.4

[feerrenrut]

The 2020.4 release needs a summary.

[CyrilleB79]

Hi, may the context help with F1 in NVDA dialogs also added to the blurb?

Moreover, while reviewing the change log, I have noted the following line:
- In web browsers and other applications that support browse mode, the Elements List dialog (NVDA+F7) can now be invoked when in focus mode. (#10453)
However, NVDA+F7 does not work in Word if not in browse mode.
cc @JulienCochuyt

[JulienCochuyt]

@CyrilleB79 wrote:

NVDA+F7 does not work in Word if not in browse mode.

Actually, in Microsoft Word, it requires browse mode to have been activated at least once. After that, the gesture works both in browse mode and in focus mode.
This limitation has originally been reported by @LeonarddeR in #10454 (comment).

[CyrilleB79]

@CyrilleB79 wrote:

NVDA+F7 does not work in Word if not in browse mode.

Actually, in Microsoft Word, it requires browse mode to have been activated at least once. After that, the gesture works both in browse mode and in focus mode.
This limitation has originally been reported by @LeonarddeR in #10454 (comment).

OK. Confirmed on my side.