bug: Document description does not match source code

[xxm404]

Issue description

The limit-count plugin document description for rejected_code does not match source code
In document the rejected_code are optional, in source code the rejected_code are required
Source code:

Document:

I can create PR to fix it, should i modify the document or source code

Environment

• apisix version (cmd: apisix version): 1.2
• OS: ununtu 14.04

What's the actual result? (including assertion message & call stack if applicable)

What's the expected result?

Document should match the source code

[membphis]

welcome PR

[xxm404]

Hi @membphis Should I modify the document to fix it or source code to fix it?

[membphis]

fix the document is better. Make it behave the same as the source code.