Missing field for config.http_method

[ndreno]

Issue summary

No (optional) field for config.http_method in the request-transformer plugin(https://docs.konghq.com/hub/kong-inc/request-transformer/)

Your environment

• Kong version = 1.0.0
• Kong Dashboard version = 3.3.0 (Kong Dashboard versions before 3.0.0 aren't supported anymore)

Issue description

Could be great if we could add this field to be able to transform one GET to POST for example

Current behavior

no field on the plugin page

Expected behavior

optional field

Steps to reproduce

Add Request-transformer plugin to an API/Service