Fixing Spell Check Notification Format

[hylstonnb]

Spell check notifications were being displayed such as:

• Changed to display the The string ... contains misspelled words just once instead of repeating the phrase when more than one misspelled word was found. Please note that unit tests have good output sample to look at.

• Changed * to ● because the spell check slack notification was not being rendered as bullet point.

• Updated unit tests accordingly

[aurambaj]

Nice, thanks for the improvements!