docs: update README to correct code snippets and add resend OTP endpoint

[12138zhen]

What kind of change does this PR introduce?

docs: update README to correct code snippets and add resend OTP endpoint. fix #1711

[kangmingtay]

@12138zhen thanks for adding this!

[coveralls]

Pull Request Test Coverage Report for Build 12527268986

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 64.735%

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Totals
Change from base Build 12515002003:	0.0%
Covered Lines:	9742
Relevant Lines:	15049

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💛 - Coveralls