Update doc

[linsang21]

Issue #, if available:

Description of changes:

Testing done:

Manual test cases (add more as needed):

• Join meeting without CallKit
• Join meeting with CallKit as Incoming
• Join meeting with CallKit as Outgoing
• Leave meeting
• Rejoin meeting
• See metrics
• See attendee presence
• Send audio
• Receive audio
• Mute self
• Unmute self
• See local mute indicator when muted
• See remote mute indicator when other is muted
• Enable and disable local video
• Enable and disable remote video from remote side
• Send local video
• Pause and resume remote video
• Switch local camera
• Receive remote screen share

Integration validation (required before release)

• Unit tests pass
• Build SDK against simulator with release options
• Build SDK against device with release options
• Build SDK against simulator with debug options
• Build SDK against device with debug options
• Test Demo against simulator with SDK (debug build) in workspace
• Test Demo against device with SDK (debug build) in workspace
• Test DemoObjC against simulator with SDK (debug build) in workspace
• Test DemoObjC against device with SDK (debug build) in workspace
• Test Demo against simulator with SDK.framework (release build)
• Test Demo against device with SDK.framework (release build)
• Test DemoObjC against simulator with SDK.framework (release build)
• Test DemoObjC against device with SDK.framework (release build)

Screenshots, if available:

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov]

Codecov Report

Merging #466 (c1887f5) into development (a6b0870) will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff              @@
##           development     #466   +/-   ##
============================================
  Coverage        71.28%   71.28%           
============================================
  Files              195      195           
  Lines             6460     6460           
============================================
  Hits              4605     4605           
  Misses            1855     1855