Add Cursor to the key-repeating help section in README

[gg-martins091]

Fixes #9500

What this PR does / why we need it:
It adds the command needed to enable key-repeating in Mac for users of the Cursor IDE. As well as separating the commands for each IDE in separate code blocks instead of one code block with comments.

Which issue(s) this PR fixes
#9500

[ykka]

Heads up that I had no success using defaults write "$(osascript -e 'id of app "Cursor"')" ApplePressAndHoldEnabled -bool false with Cursor. The problem doesn't seem to be with the interpolated id of the app but the approach in general.

What worked for me was: defaults write -app Cursor ApplePressAndHoldEnabled -bool false, so I'd consider adding this to the cursor part as a potential fallback if the first, plausibly correct way, doesn't work.

It also seems that the latter overwrites the former one. Even if I set the defaults write com.todesktop.230313mzl4w4u92 ApplePressAndHoldEnbabled -bool true and defaults write -app Cursor ApplePressAndHoldEnabled -bool false, Cursor receives the repeated key strokes.

Cursor Version: 0.50.4
VSCode Version: 1.96.2