Seeking contributions to add anyOf and oneOf

[dgreene1]

Swagger supports JSON Schema's anyOf and oneOf.

• oneOf is analogous to the | (i.e. TypeScript union)
  • Could find inspiration from typescript-json-schema's implementation (but be wary because JSON Schema is not equivalent to Swagger/OpenApi): https://github.com/YousefED/typescript-json-schema/blob/4f2d3da6f3f1ae3e1641b6777324c888a21264a3/typescript-json-schema.ts#L220
• allOf is analogous to the & (i.e. TypeScript intersection/aggregate)
  • Could find inspiration from typescript-json-schema's implementation (but be wary because JSON Schema is not equivalent to Swagger/OpenApi): https://github.com/YousefED/typescript-json-schema/blob/4f2d3da6f3f1ae3e1641b6777324c888a21264a3/typescript-json-schema.ts#L660
• Both keywords have separate validation criteria as described here: https://stackoverflow.com/a/34038277/706768

For those people who need a workaround, please check out: #391

[dgreene1]

went live in v2.4.11