doc errata

[Hokwang]

Hi,

I think I find some problem in your web-site.

1. please look at https://docs.gitea.io/en-us/config-cheat-sheet/#oauth2-oauth2/
   there's

oauth2:
  ENABLE: true

but, I think ENABLED (add D) may be right. please make consistency with other's.

2. please look at https://docs.gitea.io/en-us/config-cheat-sheet/#openid-openid
   I think
   ENABLE_OPENID_SIGNUP: ! DISABLE_REGISTRATION: Allow registering via OpenID.
   has problem.

[lunny]

@Hokwang Could you send a PR?

[noerw]

Ad 1: the docs are correct, the setting is named ENABLE. This is inconsistent with other ENABLED settings, but due to already high complexity in settings parsing, this is most likely a wontfix

Ad 2: this is also correct, although ENABLE_OPENID_SIGNIN obviously needs to be true too.