* add `onFound` callback to schemas
* add warning to method docs (for #4957)
* implement Docker OAuth2 init block support
* update docs
* add OAUTH_SCOPE_SEPARATOR
* drop OAuth env from Dockerfile and run script
* don't indent the first oauth block line
* drop unused `dedent` import
* touch up warning message
* add more test cases
* return an empty block if no OAuth content is generated
* fix broken doc line
